Archive for the ‘Automotive Knowledge’ Category

The magic computer? We still don’t have one.

Thursday, July 20th, 2017

“Do you have one of those computers that tells you what’s wrong with the car?” This has got to be one of every mechanic’s least favourite questions to get from a customer. As we’ve explained before, while scan tools can provide a starting point for a proper diagnosis, it’s very early in the process that the human brain must take over. As we often tell people, there is a big difference between pulling out a trouble code and actually diagnosing a problem.

Here’s a great example from this week. This little Honda CR-V came to us with a “check engine” light on, and the engine idling rough.

airdrie check engine light

 

We connected a scan tool and retrieved the stored trouble codes from the engine computer, or ECM. As we often see, the stored codes were of no help, as the engine had set misfire codes for all four cylinders. We already knew the engine was misfiring, and the trouble codes don’t tell us why the misfire is happening.

airdrie car scan

 

Even though this vehicle’s rather simplistic engine computer is flagging misfires on all four cylinders, the issue really felt more like a consistent misfire from a single cylinder. Removing and shorting out the spark plugs wires one by one, we determined that the engine was misfiring on cylinder #4.

airdrie spark plugs

 

OK, now what? We’ve got lots of possibilities here: the issue could be a bad spark plug or plug wire; a problem with the distributor (yes, this car still has one); a faulty fuel injector; or about a dozen other things. Removing and inspecting the cylinder #4 spark plug seemed like a good place to start. As it turns out, the spark plug and wire were both in good condition.

airdrie mechanic

 

We noticed, however, that the spark plug was a bit wet with fuel. Having already ensured we had a strong spark supply to the plug from the distributor and coil, this could only mean one thing: The spark plug was firing; the fuel injector was firing; but the combustion event was not taking place inside the cylinder. The next logical step seemed like performing a compression test. We installed our compression tester in the #4 spark plug tube; disabled the ignition system; and cranked the engine over. As it turned out, cylinder #4 was only making about 40PSI of compression! (A good cylinder on this engine measured around 160 PSI.)

airdrie compression test

 
The low compression was definitely the cause of the misfire. Every engine needs at least 100 PSI per cylinder to “get the fire going”, so to speak. Now it was time to determine why cylinder #4 had low compression. Like before, there are lots of possibilities: it could be a burnt/bent valve; worn out piston rings; or a handful of other things. How do we determine where all that lost compression is going? We install a cylinder leakdown tester. Out came the compression tester, and in went this next tool.

airdrie car repair

 

We rotated the engine until cylinder #4 was on its compression stroke, with all the valves closed. Using the leakdown tester, we filled the cylinder with compressed air. As you can see, this cylinder has about 85% leakdown. (20% is the most we’d ever like to see on a good engine.)

We can also use the leakdown tester to determine where the leaking compression is going, by listening for air leakage at different points on the engine. Air coming out of the intake manifold or throttle body indicates a leaking intake valve on this cylinder. Air hissing from the tailpipe indicates a leaking exhaust valve, and air leaking from the oil cap points towards a leak into the crankcase via worn out cylinders and/or piston rings. This vehicle had none of these leaks. The compressed air was actually leaking from the cylinder #3 spark plug hole, indicating there is a blown head gasket or other combustion leak between these two adjacent cylinders.

The next step in diagnosis will be to remove the cylinder head for inspection, and likely replace the leaking head gasket.

 

Almost every warning light diagnosis works this way. The trouble codes (sometimes) provide a starting point, and then there are usually many other tests that must be performed – using even more specialized equipment – to “zero in” on the route cause of the issue. With some issues, there are no codes stored at all, and the technician must let the symptoms and their experience lead them in the right testing direction.

Every good diagnosis goes like the one on our Honda this week: A well-trained technician knows exactly what test to perform next based on the symptoms at hand, and lets the results of that test tell them what test should be performed afterwards. There is no wasted time troubleshooting parts that don’t need to be checked – and more importantly, no money wasted replacing parts that won’t fix the problem.

This is the value of a good diagnosis by a qualified professional, and it’s what we work to bring you every day.

Getting the most out of your air conditioning system

Friday, July 7th, 2017

July has barely begun, but we’ve already been inundated with some very hot weeks in Alberta! Naturally, we’re doing lots of air conditioning repairs these days. But what if your air conditioning system works, but it doesn’t cool as well as you’d like? Here are some tips to maximize its effectiveness.

 

Change your cabin air filter.

Cabin what? We still run into a lot of people who won’t know their car has a cabin air filter! Your cabin air filter is the “furnace filter of your car”, filtering the air travelling through your heater vents. The effect a restricted filter can have on air conditioning cooling is dramatic! A plugged filter not only drastically reduces the force with which the air blows from the vents, but it also reduces cooling. Check out this vent temperature comparison we did on a vehicle with a very dirty cabin air filter:

air conditioning repair

We don’t charge any labour to replace cabin air filters on most vehicles, and we sell most vehicles’ filters for between $20 and $30!

 

Replace your climate-controlled seat filter.

Does your vehicle have air conditioned or cooled seats? Most of these have filters that require regular replacement as well. Check your owner’s manual on how often you should tend to them on your vehicle.

 

Turn your fan speed down.

As tempting as it may be to really get that cold air blasting, you’ll usually achieve a colder vent temperature at settings around three quarters of the way up your blower motor’s fan speed range. For example, this may be speed #4 of 5 settings. The faster the incoming air is moving, the less time it spends inside your vehicle’s evaporator core to be cooled, and too much air can overload the system on hot days.

 

Use your “recirculate” or “max A/C” setting.

car ac not cold

In one pass through the system, your air conditioning system can only cool the incoming air by so many degrees. By switching to your “recirculate” setting, you direct the system to pull air from inside the vehicle (which has already been cooled once) instead of outside. This dramatically reduces vent temperature on most vehicles. Just be careful on longer drives, because the air conditioning system also dries the air that passes through it. You’ll want to switch off the recirculation mode from time to time in order to avoid dry mouth or headaches.

 

Check your radiator for restrictions.

radiator replacement

For your A/C system to cool properly, it must be able to draw large amounts of air through the condenser mounted behind your vehicle’s front grille. Dirt and mud build-up on the front of the radiator and between your vehicle’s various coolers – very common on trucks – can really reduce this airflow. We’ve even seen where a customer forgot their “Saskatchewan thermostat” (piece of cardboard) behind the radiator after the winter ended! While we’re taking shots at our neighbors to the east, radiators plugged with bugs and grasshoppers are a real cooling issue in the prairies as well! Most of this debris can be washed out with a garden hose from the rear of the radiator. Be careful using a pressure washer; you’ll want to keep the angle of your spray perpendicular to the radiator or else you’ll bend the fins.

 

Have your air conditioning system recharged.

While a perfectly sealed air conditioning system should never get low on refrigerant – or “freon”, as we used to call it – the reality is that over the years, the refrigerant level may drop. Removing, measuring and topping up (or “recharging”) the refrigerant level can get your vehicle cooling like new again. This is something that should be left to a professional; see our post here on why you should not use store-bought “canned” refrigerant products. If your air conditioning system becomes low on charge after just one year or two, then it likely has a leak that should be repaired.

We charge between $140 and $180 for this service, on most vehicles.

 

Have any air conditioning system problems or concerns? Email us or give us a call!

The “extra warranty” you didn’t know your vehicle had!

Saturday, June 24th, 2017

airdrie exhaust catalytic converter

By Chris Dekker

 

This month, we had a 2011 Buick in the shop for a check engine light diagnosis. We determined that the car had a failed catalytic converter; not a cheap repair. We called the customer and informed them that while we’d love to replace their catalytic converter, we couldn’t charge them for something they could receive for free under warranty. “Warranty?” they said, “That thing has been off warranty for almost two years!”

While the customer was right – the powertrain warranty had long since expired – the catalytic converter was covered under a special, federally mandated emissions system warranty. American and Canadian laws state that car manufacturers must cover certain emissions system-related parts for 8 years, or 130,000 km. This list of parts includes:

  • The catalytic converter and any related shielding/protection.
  • The under-dash data link connector that is used with scan tools.
  • The “check engine” light bulb and related wiring.
  • The engine control module or computer (ECM, PCM, etc).
  • In addition to these parts, any other on-board computer that performs diagnostic functions related to the emission system must be covered. On some vehicles, this includes the Transmission Control Module, Fuel Pump Driver Module, and more.

While this is a fairly short list of parts, some of these items are very expensive components to replace, so it’s worth knowing about!

airdrie ecm pcm repair

 

Who can perform these warranty repairs?

Only a repair facility authorized by the vehicle manufacturer themselves can perform a no-charge repair under your emissions warranty. In most cases, this will only be the servicing dealership for that brand.

Can I be charged for any part of an emissions warranty repair?

No; it’s forbidden by law. While many dealerships will ask you to commit to a diagnostic charge up front, in case your problem isn’t actually being caused by one of the warrantable parts, they cannot charge you for this diagnosis once it is determined that a warrantable part has failed. You are not to be charged for the diagnosis, or any additional parts and/or supplies that are required to complete the repair. For example, if a catalyst replacement requires installation of new exhaust gaskets, pipes or clamps, you should not be charged for these items either.

Is there any way a dealership can deny an emissions warranty claim?

Yes – but only if they can prove that you have misused your vehicle or not maintained it correctly, and it is this abuse that caused the failure of the warrantable part. Some examples of these abuses include:

  • Vehicle abuse such as off-road driving or overloading.
  • Tampering with emissions system components, including removal; intentional damage; or disabling of any emissions parts. (This would include installation of many aftermarket performance parts; “chips”; or “programmers”.)
  • Improper maintenance, such as not following the manufacturer’s service schedules, or not using replacement parts that are equivalent to factory parts. For example, let’s pretend your owner’s manual states to replace your spark plugs at 100,000 km. If you bring your vehicle in with a failed catalytic converter at 120,000 km, and the original spark plugs still installed, it could be argued (and fairly so) that the worn-out spark plugs caused an engine running condition that damaged the catalytic converter.

What should you do if your claim is denied, and you’re sure it shouldn’t have been?

  1. Ask for a detailed explanation, in writing as to why emissions warranty coverage was denied; and
  2. Ask for the name(s) of the person(s) involved in the decision to deny coverage, including anyone from the manufacturer’s regional or zone office; and
  3. Ask for the name(s) of the person(s) with the manufacturer you should contact to appeal the denial of coverage under the emissions warranty.
  4. Contact the person mentioned above requesting coverage and giving the basis for your request. Repeat and continue the appeal process until you are satisfied or have exhausted all means of appeal. In Alberta, motorists can also reach out to the Alberta Motor Vehicle Industry Council (AMVIC) for help with any auto purchasing or service issues.

We hope this information is helpful, and we’d be happy to answer any questions you may have about new vehicle warranties – or anything else car-related! Please call or email us anytime.

The technician or the tool; what matters more?

Sunday, January 31st, 2016

airdrie mechanics

By Chris Dekker

 

We’ve seen some shops use really nice, state of the art alignment machines to turn out some pretty bad wheel alignments; and we’ve seen shops with much older, basic machines perform some really good ones. In terms of our alignment machine, anywayn we’re definitely part of the group with the older, not-so-fancy units! So what makes the difference? It’s the person running the machine, and how much they care.

This month, our technician Dan really impressed us – and our customer – with his dedication to “getting it right” and making a big, lifted truck steer better.

A proper alignment includes adjustment of three suspension angles: caster, camber and toe. Toe angle, the most important one, describes where the wheel is pointing, or steering. Camber describes how much the top of the wheel leans inwards towards the vehicle, or outwards.

Caster angle is the hardest to adjust, and the hardest to explain. It’s what makes the vehicle steering return to centre when you complete a turn, and what helps the wheels stay pointed straight down the road. Have you noticed how a shopping cart’s wheels always stay pointed forwards as you push it? How is that, when there’s no way to steer them? That’s an example of positive caster angle at work.

 

airdrie wheel alignments

 

If a customer isn’t paying attention, toe angle might be the only one that gets adjusted by some businesses. “Set the toe, collect the dough and let ‘er go” is a popular joke amongst commission-paid mechanics. The 2007 Ford F-350 that our customer was so impressed with us about had perfect camber and toe – and it should have, because the customer had already been to two shops who told him the alignment was as good as it could get! However, the truck was still “all over the road” and not enjoyable to drive at all.

Dan put the truck on our alignment rack and found that the caster angle was way too low. Both sides were around -1.0 degrees, and Ford’s recommended specification was between +1.0 degrees and +2.0 degrees! Caster angle that’s 2-3 degrees too low will cause problems in itself; but we’d never seen NEGATIVE caster on a vehicle before! In theory, this would make a vehicle very hard to steer – and in practice, it did!

So what could we do about the low caster? The new lower control arms that were included in the lift kit didn’t include a caster adjustment like the factory control arms do; so that was out. What if we fitted adjustable control arms? That sounded like a good idea until we realized that by twisting the axle backwards to increase caster angle, we would exacerbate an already very steep pinion angle on the front driveshaft; so that option was out. We didn’t need this truck steering better but suddenly burning out universal joints once a month!

Dan had one more idea. The upper ball joints on these trucks bolted to a metal insert, which presses into the steering knuckle, and differently shaped inserts can be ordered to move the ball joint forwards and backwards to change caster angle. But these were only meant to accomplish small adjustments; would it be enough? We decided to try.

We set to finding the most extreme insert we could find, with the absolute most adjustment possible. We found some, and ordered two. Dan removed the upper ball joint nuts and pressed the factory inserts out. When the new inserts arrived, he oriented them in such a way that they would move the upper ball joints as far backwards as possible, to increase caster angle the most he could, and pressed them in. Back onto the alignment machine went the truck.

We had hoped for a bit more improvement, but were nonetheless relieved to see the caster angle around +1.2 degrees on both sides. This was just barely within Ford’s acceptable spec, but more importantly, was at least 2 degrees higher; positive; and in the right direction!

On the road, the 2 degree improvement in caster angle translated into a huge difference in how the truck drove. The owner actually called us a few days later to thank us again for fixing his “unfixable” truck! We told him not to thank us, and thanked him, for choosing to service his vehicle with us. After all, we were only doing our job; old alignment machine and all!‎

Cleaning intake valves, using crushed walnut shells!

Wednesday, October 14th, 2015

By Chris Dekker

 

During the 1980s, there was an important shift in the automotive industry: carburetors were out, and fuel injection was in. While a carbureted engine basically sucks in a stream of liquid fuel, a fuel injected engine uses an electronic fuel injector (which is controlled by a computer) to deliver a burst of high-pressure fuel mist at precisely the right moment. Think of a Windex bottle; the stream setting mimics a carburetor, while the mist setting is your fuel injector.

Most fuel injected engines from the last 20 years use port fuel injection, where fuel is injected upstream of the cylinder into the intake manifold. The fuel spray is carried past the intake valve, and into the cylinder (where it is burned) by the flow of air into the cylinder. Remember this part about fuel passing through the intake valve, as it gets important later!

Liquid gasoline has a hard time burning; it’s the vapor that really gets things going inside your engine. The mist delivered by a fuel injector atomizes easier, and burns more completely. This more complete burn – combined with the improved control from having a computer running things – translates into better fuel economy and decreased emissions. Now imagine that we could take that mist from your Windex bottle, crank the pressure way up, and shoot that pressure through tiny holes so small that the human eye can barely see them. The fuel spray would be super fine; how well would that burn?

 

direct injection

This idea is part of a new technology called direct injection. Direct injection also offers another advantage: it delivers its super-high-pressure fuel spray directly into the cylinders of your engine, right beside the spark plugs. Compared to port injection, direct injection offers even better control of the combustion event, and even better performance. Gasoline direct injection (GDI, for short) is getting more common in our industry, as car manufacturers continue to chase better fuel economy and cleaner emissions. GDI can help a small engine to make as much horsepower as significantly larger one, as Ford has demonstrated with their popular Ecoboost engines.

 

airdrie auto diagnostics

 

However, moving the fuel spray from the intake manifold to inside the cylinders had an unexpected conseqeuence: bad deposit build-up on the intake valves. It turns out that the continuous fuel spray onto the intake valves in a port-injected engine did a good job keeping them clean. Deposit build-up on the intake valves of GDI engines has become a big problem; causing misfiring, hard starting and poor performance.

 

carbon buildup valve

This nasty build-up is composed of:

  • Carbon from the combustion of fuel, which is pushed back out of the cylinders.
  • Trace amounts of engine oil that leak past the valve seals, or are carried into the intake manifold by the crankcase ventilation system.
  • Exhaust soot that is recirculated back through the intake manifold by the EGR (an emissions control) system.

 

This all combines to create a rock-hard, clumpy layer of junk on the intake valves that gets thicker and thicker over time. Eventually it builds up to the point where airflow through the valve is restricted, or the valve cannot open and close properly.

The photo above is from a Mazda that we serviced this week, and is the worst example of this build-up that we have seen to date. This engine had less than 150,000 kilometers on it, and a bad misfire that was due in part to the valve issues. With this Mazda, we decided to do a little experiment. As GDI becomes more common in our industry, so too do the problems with intake valve deposits. Several companies have responded with various products designed to clean off these deposits, including CRC with their GDI-specific “Intake Valve Cleaner”. But do any of them work?

Most of these products are a liquid designed to be “fogged” into the intake manifold as the engine runs, where they will travel through the intake valves and hopefully remove some of the deposit build-up as they pass by. The trouble with these products is that you normally never get to see how well they work (or don’t work), since the valves are hidden deep inside the engine. With this Mazda, we had the intake manifold removed and full access to the valves – so we decided to try several popular products to clean the valves directly. We chose CRC Intake Valve Cleaner, Sea Foam Motor Treatment, ACDelco Cleens Combustion Chamber Cleaner, and a last-minute crazy idea: Wipe-Out, a very powerful gun cleaner designed to remove carbon and copper fouling from rifle barrels.

airdrie auto repair

 

First we sprayed each of the valves with one of the cleaning products, let them soak for a couple minutes, then blew out the intake runners with compressed air. Initial results were disappointing: none of these products magically dissolved or removed any of the build-up through contact with the valves alone. Experience told us not to expect this anyways, but it would have been nice!

Next, we tried a longer, ten minute soak and then a good scrubbing with a small toothbrush before blowing out the ports again. A tiny amount of deposit was removed from each valve, with all of the products working about the same, but we were barely making a dent. We could tell that completely cleaning the valves this way would probably take days; not an economical choice for the customer!

It was the end of the day, so we decided to fill each intake port with cleaning product and let the valves soak overnight. The next morning, we gave each valve a good picking-at with a dental pick, and then a scrubbing with the toothbrush before blowing out the ports. The Wipe-Out seemed to work the best, but barely. We were hoping that “thinking outside the box” would produce an industry-leading breakthrough here, but it was not meant to be. All of the products loosened up an outer layer of the build-up, but 80% of the deposits remained.

One important note: Most of these products are designed to work in the presence of heat on a running engine, which should make the carbon build-up easier to remove. This was impossible with the engine disassembled, of course. However, we’d like to believe that if overnight soaking, scrubbing and brushing will not remove much of the build-up, 2-3 minutes of misting onto the valve will not work either.

At this point, it seemed that the various cleaning products, like much of the snake oil bottles on the parts store shelves, were a chemical solution to a mechanical problem, and just weren’t going to work. No chemical was going to remove these deposits, and pulling the cylinder head to remove the valves would cost thousands of dollars. There had to be a better way. It was after a little research that we came across another popular solution: sand-blasting the valves with crushed walnut shells.

 

airdrie car repairs

 

The crushed walnut shells are abrasive enough to remove the deposits, but not enough to remove metal from the valves or cylinder head. After a quick phone call, we had a big 30 pound bag of crushed walnut shells to play with, and decided to try this technique out. Now, we were making progress! It still took a lot of careful work, but the sandblaster did a nice job of cleaning the valves.

The walnut shell grains proved a bit too large for our recovery system to handle, though. A few hours later, poor Richard had walnut shells everywhere – in his hair, his clothes, and even his nose – but the Mazda had some much better looking valves!

 

airdrie auto service

 

The crushed walnut shell technique offers a good value in that it’s much more effective than most cleaning methods, and still relatively quick; definitely the way to go in a case like our Mazda here.

Having fixed this one, our focus now shifted to preventing this problem in the first place. Would some of the commercial cleaning products work better if used every 10-20,000 kilometers, as maintenance to prevent this build-up? Is this a service we should be recommending to our customers who own direct-injected vehicles?  We don’t want to sell a product that our customers will not receive a substantial benefit from. Continued research over the coming months should give us these answers, and we look forward to sharing more with you!

 

Why “A/C in a can” is a bad idea.

Saturday, August 15th, 2015
airdrie auto air conditioning

This is an example of an “auto parts store” A/C recharge kit.

By Chris Dekker

 

Air conditioning refrigerant, sometimes referred to as “freon”, is the liquid that circulates through your car’s air conditioning system and makes the system cool. The refrigerant that has been used in vehicles since 1995 is called R-134a. Your refrigerant should theoretically never need topping up or changing, but the reality is that it can sometimes leak out over time, and your vehicle’s air conditioning may start to work poorly. (If a leak is found, it should be repaired, of course!) This post explains why an increasingly popular air conditioning “solution” is actually a bad idea.

While browsing your department store, you may have come across small cans of aftermarket, hydrocarbon-based refrigerant for sale, including brands like Duracool, Red Tek, and Emzone 12A. Should you use these products to “top up” your air conditioning system, and get it cooling well again? These products claim to offer better cooling (because they are a more efficient refrigerant), and be easier on the environment, so it sounds tempting. They’re cheap, too. While these claims are partially true, there are a bunch of reasons why you still shouldn’t put them in your vehicle’s A/C system:

 

Reason #1: You can’t recharge your system properly.

A proper, long-lasting air conditioning recharge procedure includes the following steps:

  1. Evacuate the old refrigerant from the system, and weight it to determine if the system was over, or under-charged.
  2. Measure the amount of oil that was removed from the system.
  3. Using an electric vacuum pump, pull a vacuum on the system for at least 15 minutes to draw out any trapped air, and boil off any water in the system. (Water boils at room temperature when under a vacuum!)
  4. Leave the system under vacuum for at least 10 minutes after stopping the pump, and monitor rate of vacuum drop to test the system for leaks.
  5. Add the appropriate amount of oil to the system. There is a minimum amount of oil required to protect system components; but too much oil will insulate the lines and reduce cooling.
  6. Charge the system with a specific weight of refrigerant. Too little refrigerant will result in poor cooling, and too much will create high running pressures, also causing poor cooling.
  7. Run the system and monitor high and low side pressures; temperatures; cooling fans, etc, to make sure everything is working properly.
  8. Add an ultraviolet dye to the system, so if any leaks develop, they can be located with a UV light and glasses.

The “refrigerant in a can” kits only address step #6, and poorly at that. There is no way to accurately measure how much refrigerant is added, and no way to pull all the air out of the system before adding it.  This means you are injecting an unknown amount of one refrigerant on top of an unknown amount of a different refrigerant (plus any air and water in the system), with an unknown amount of oil. It’s not hard to see why the results are often less than stellar.

So what happens if you try a hydrocarbon-based refrigerant, and your A/C still doesn’t perform as desired? Maybe now, it’s time to bring your car to a professional. But that brings us to problem #2…

 

Reason #2: Once a hydrocarbon-based refrigerant is added, most professional mechanics will not touch your A/C system.

What’s an azeotrope? It’s a mixture of  two different refrigerants, which when mixed, exhibit unique and undesirable properties. By adding a hydrocarbon-based refrigerant to the haloalkane factory refrigerant, this is what you create. This mixtures of refrigerant often behave unpredictably, and don’t function right in an A/C system.

Azeotropes cannot be disposed of in the same way that you could with a pure refrigerant such as R-134a. In Alberta, azeotropes are treated as a hazardous waste and must be disposed of at the Swan Hills treatment facility, at a cost of over $300 per pound. You can see why no shop would want to contaminate their R-134a tanks, or their A/C equipment with a hydrocarbon-based refrigerant!

We (and most other businesses) use an expensive tool called a refrigerant identifier, before we hook equipment up to your A/C system. It lets us take a sample of the refrigerant in your system, and analyze it to find out what chemicals it’s made up of. If we find hydrocarbons in the system, we have to inform the customer that we cannot service their air conditioning.

 

airdrie auto ac

Here is our refrigerant identifier, taking a sample on a customer’s vehicle. This is a $3000 tool!

 

Reason #3: Hydrocarbon refrigerants are flammable.

That’s right! Most of these “canned” refrigerants are made up of a light hydrocarbon such as propane. Propane actually has the right boiling point to make an excellent refrigerant, if it wasn’t for the safety concerns involved. In the event of a front-end collision where the air conditioning condenser or hoses were punctured, high pressure refrigerant spraying out at over 100 PSI could cause an inferno in a matter of seconds if it comes in contact with something hot under the hood. The chances are low, but this situation is certainly possible, and does happen. Refrigerant vapour under the hood can even be ignited by a leaking spark plug wire.

 

The “A/C in a can” solution is tempting for somebody who doesn’t know better: it’s quick, easy and cheap – but as you may now understand – could end up costing you a whole lot more than just servicing your system properly in the first place.

Your Car is Lying to You! (But it’s OK)

Friday, May 15th, 2015
Airdrie Ford Repair

The oil pressure gauge in this 2005 Ford F-150 always reads exactly the same, regardless of what the actual pressure is.

By Chris Dekker

 

The technology being integrated into new vehicles is amazing, but sometimes takes some getting used to.

A great example of this was the integration of “smart” charging systems into late model Chevrolet and GMC trucks. To save fuel, the alternator can “shut off” during periods of low electrical demand, which reduces drag on the engine. During driving, it’s totally normal for the battery voltage to fluctuate anywhere between 10 and 17 volts –  a big difference from the days of old where 14 volts meant your alternator was charging properly, and 12 volts meant that it wasn’t.

This change had unexpected consequences: GM dealerships were flooded with customers who, after watching their battery voltage gauge, thought their trucks were experiencing an electrical failure – and GM wasn’t alone in this. Do you know what many car manufacturers did to fix the problem? They eliminated the gauge.

But this isn’t always a good solution. Truck buyers, in particular, are a traditional bunch; and they have grown accustomed to all of these different gauges (oil pressure, engine temperature, battery voltage, transmission temperature, etc) and the information they provide. Many won’t purchase a truck without these displays, which has lead to a new development in recent years: the introduction of gauges that “lie” to the driver.

Maybe “lie” is a little harsh. These gauges fib a bit. Many analog gauges in newer vehicles are programmed to show one reading all the time, as long as the reading they’re supposed to display falls within an acceptable range. Unfortunately, this means some vehicles are now filled with instruments that no longer display any real information at all. For example, the oil pressure gauge in a 2004+ Ford F-150 always displays exactly the same reading (about 2/3 up) as long as the engine is making any oil pressure at all – even if the pressure is less than the 25 PSI that Ford specifies as the bare minimum necessary. This is undoubtedly to avoid confusing customers, who may not understand how normal oil pressure starts off very high from a cold start, and drops sharply as the engine warms up. In fact, every gauge except the tachometer and the speedometer in the 2005 F-150 instrument cluster shown above is “dumbed down” to some degree.

This isn’t just a Ford thing; most car manufacturers are doing this. Most Volkswagen temperature gauges now read exactly in the middle, as long as the coolant temperature is between 65 and 110 degrees Celsius, to avoid worrying customers with normal changes in engine temperature. Other car makers have moved from an analog temperature gauge to a system of simple warning lights: a green light means the temperature is OK, and a red one means it’s too hot or too cold.

It’s easy to understand why car manufacturer’s have moved to these “idiot gauges” in an age where most car owners don’t even check their own oil any more. However, as someone who appreciates the information an accurate display can provide, it’s frustrating as well. If anything, this lack of real information for the driver further underscores the importance of having a qualified mechanic check over your vehicle regularly!

Why Your Winter Fuel Economy Stinks

Sunday, January 25th, 2015

Airdrie Mechanic Fuel Economy Tips

Recently, we’ve had a lot of customers come in concerned about poor fuel economy. Sometimes there are repairs or adjustments that we can make to improve their mileage, and sometimes it’s the customer’s expectations that need a little tweak.

We could write an entire article on why your car will never match it’s EPA advertised fuel economy ratings – the “highway” test is done at an average speed of 77 km/h, for example – but there’s another reason why your mileage might be worse right now: it’s winter! The US EPA says you can expect between 10-22% lower fuel economy, depending on how you drive, at -10 degrees vs +25 celsius. Let’s explore the reasons why your car gets so thirsty this time of year.

  • The fuel itself. Gasoline in its liquid form doesn’t really burn. The engine needs to vaporize the fuel, usually by injecting a very fine mist at very high pressures. Unfortunately, gasoline and diesel don’t vaporize as easily at cold temperatures, so fuel manufacturers produce “winter blends” that vaporize more easily to prevent hard starting and rough running. However, this fuel has less heat energy available and produces less power to propell your vehicle, resulting in lower mileage.
  • It’s a mess out there. Driving for winter road conditions naturally burns more fuel. Pushing through snow and ice demands extra energy, as does using four wheel drive more often. You may even be forced to slow down sooner, instead of being able to coast to faraway stops.
  • Your tires. The cold weather, and repeated warm days/cold nights cause your tires to lose pressure more quickly. As we know, low tire pressure increases rolling resistance and lowers fuel economy. Even when your tire pressure is OK, the rubber tires themselves are still stiffer in the cold. This means they don’t flex as easily and rolling resistance is still increased.
  • More electrical load on the engine. Any electrical current that you use has to be produced by the alternator, which puts more load on the engine. In the winter, we’re using our rear window defroster (which is one of the largest loads in the vehicle), the heater, heated seats/steering wheels, etc. We’re probably using the windshield wipers more, too. And if you think these loads might be balanced out by air conditioning use in the summer, consider this: Whenever your heater controls are in the “window defrost” or “floor/window mix” modes, your air conditioning compressor is actually running in order to dry the air and avoid fogging up your windows.
  • Colder air. Colder air is denser, and this affects your vehicle in a number of ways. Because of the aforementioned fuel vaporization issues in the cold, your car actually takes steps to avoid running rough, including running a “richer” air fuel ratio. This means injecting a little extra fuel because it knows that not every bit of fuel that goes through the engine will actually get burned. Denser air also provides more aerodynamic resistance, holding your car back and requiring more fuel to push through. Density is the reason it’s harder to walk through water in a swimming pool than through the air.
  • Your fluids are thicker. Average lubricant viscosity is higher when it’s cold, which means your engine oil, transmission fluid and differential gear oils are all thicker. This translates into extra drag on the gears, bearings, chains etc throughout your powertrain, which means wasted energy. Even your power steering fluid viscosity is higher, placing extra drag on the power steering pump (and the engine).
  • Idle time. This one is huge. 15 minutes of voluntary idle time every day can burn 1.5 cups of fuel for cars, and 3 cups for trucks. This translates to 3-5 litres over the course of a week, or a loss of between 20-40 km per tank for the average commuter who fills up once per week. Double the idle time, (let’s say you warm up your car in the morning, then again before you leave work in the afternoon) and this loss becomes 40-80 km per tank.

 

So, with all these factors working against you, what can you do to improve your winter fuel economy as much as possible? Here are some ideas:

  • Idle your engine less. 30 seconds of idling is all your engine needs before it’s “safe” to drive, even at very cold temperatures. Just go easy on it until your temperature gauge starts climbing.
  • Use your block heater. Besides reducing engine wear, your block heater allows your engine to reach operating temperature more quickly where it isn’t running a “rich” air/fuel ratio. This will also allow you to reduce warm-up idle time and heater usage. It even warms up thick engine oil and gets it pumping more freely.
  • Replace that worn thermostat. Does your coolant temperature gauge reach its normal level in the cold, or does it struggle to climb as the mercury falls? If your engine isn’t warming up as normal, it’s more than just an annoyance; it’s costing you money in the form of extra fuel that must be burned. You’ll enjoy the improved heater output from replacing that old thermostat, too!
  • Use your manufacturer’s recommended winter grade of oil. Did you know that most car manufacturers recommend different “weights” of oil, depending on what time of year it is?
  • Use synthetic oil. Many vehicles already spec full synthetic oil, and you know that we adhere to those recommendations when they apply. But if your car doesn’t call for synthetic oil, you can still use it and enjoy the reliability and fuel economy benefits – which are the most aparent in cold weather.
  • Say no to “universal” fluids. The most common area where multi-vehicle transmission fluids, power steering fluids, etc don’t meet your vehicle’s specified requirements is their “low temperature pour point” spec. This means they’re thicker than they should be when cold, causing extra drag and potentially damaging your vehicle.
  • Check your tire pressures regularly.

Explaining the Diagnostic Process

Sunday, October 12th, 2014

Airdrie Automotive Diagnostics

 

The other day, a customer called us to ask if we had “one of those computers that tells you what’s wrong with the cars”. I was tempted to make a goofy response like “Yes, and I have robots that fix them for me, too!”, but I knew what they meant. The customer was talking about a scan tool. And of course, we do have scan tools; four different ones, in fact.

Scan tools have been around for decades and became a very necessary tool in the 1980s as vehicles switched from carburetors to fuel injection, which of course meant they now had an on-board engine computer. Today’s vehicles have between 5 and 50 on-board computers; the scan tool is a device that lets a qualified technician communicate with these on-board computers in order to diagnose problems, test systems, and make software changes. Today’s scan tools – many of which aren’t actually “tools” anymore, but laptop-based programs – are pretty advanced. That being said, most customers don’t realize how little the scan tool actually contributes to an accurate diagnosis, and how quickly in the process the human brain must take over from the tool.

One of the more regular things that we use a scan tool for is to diagnose a warning light, such as a Check Engine or ABS light. Whenever a warning light comes on, this means that an on-board computer has detected some sort of problem, and stored a “trouble code” as a result.  In the case of the Check Engine light, these codes read something like P0302 or P0171. Any code starting with P0- is universal between most vehicles, so the scan tool will usually add a definition so they read P0302 – Cylinder #2 Misfire and P0171 – Fuel System Lean, Bank 1.  Retrieving these trouble codes from the vehicle is usually a quick process, and this is where two common customer misconceptions (and sometimes, sources of frustration) come from:

  1. Because the code retrieval process (which is only the start of the diagnosis, as we’ll get to in point #2) is so quick, customers sometimes feel ripped off when they are charged $100-150 for this service. This is partially our fault, as most shops will show the service as a one hour charge on the invoice. If the service doesn’t take this long, it’s only natural for customers to get upset. It’s very important for us to explain that we’re billing customers for a $120 charge vs one hour’s labour. This might be the same dollar amount, but we need to justify the charge for what it really is: in part, a way to earn back the purchase cost of the scan tools being used. In total, our four scan tools cost over $25,000 and require another $3500 in software updates every year.
  2. Many customers also don’t realize that retrieving a trouble code is only part of properly diagnosing an issue. This is partially because we as professionals haven’t done a good enough job educating consumers; parts stores that will “pull a code for free and then sell you a part” aren’t helping the situation. For example, what’s causing that P0302 – Cylinder #2 Misfire? Is is a spark plug? A plug wire? It could also be an ignition coil, a fuel injector, a wiring problem, a bad sensor, a vacuum leak – even a mechanical condition such as low compression on that cylinder, a sticking valve, or broken valve spring. This is where a properly trained technician – and a whole bunch more test equipment – are required to narrow in on the real problem.

 

Here are some of the steps a properly trained technician will take in order to diagnose most Check Engine lights, once the easy part (pulling the code) is complete:

  • Using the scan tool, monitoring the PIDs (or parameter IDs) for the affected module. These are hundreds of numbers that the scan tool spits out in real time, constantly updating them many times per second. These can be temperature readings, voltages, duty cycle (on/off time) numbers, resistance values and more; and they have confusing names like B1S2 Ho2S, VGT DUTY % and VREF, etc:
    Airdrie Auto Diagnostic Numbers

    Some basic engine PIDs being graphed

    None of these numbers really tell you anything by themselves; it takes a skilled technician to know which ones are relevant to the problem being experienced, and to understand the relationship between these numbers. (When number A increases, number B should increase at the same rate, while number C decreases at half that rate, etc.) Interpreting all of these numbers will help the technician understand what’s going on inside the engine, and narrow on on which part of the engine is having trouble.

  • The technician will likely also consult published service information from the vehicle’s manufacturer – which we subscribe to – in order to familiarize themselves with how certain systems work, what readings to expect, etc. It’s impossible to remember everything about every single vehicle on the road, which makes the tech’s ability to understand service information, diagrams and wiring schematics very important. These service information subscriptions aren’t cheap, either – but like the scan tools, are a very necessary part of a shop’s tools and equipment budget.
  • The tech will probably also check for Technical Service Bulletins (TSBs). These bulletins, released from the auto manufacturers to service facilities like ours, serve to alert us to common issues we should know about. They may also contain information on updated test procedures, updated fluid recommendations, new specialty tools that have been released for a given repair, revised/improved parts that are available to fix certain issues, and more. A quick check of the TSBs will help the technician ensure they aren’t missing any important information that they need to diagnose an issue accurately and carry out a proper repair that lasts as long as possible.

At this point, the technician has probably exhausted all of the information that the scan tool, and their computer, can give them. Finalizing the diagnosis will probably require some hands-on testing with a variety of other tools. Sticking with the P0302 – Cylinder #2 Misfire, the tech may use:

  • An ohmmeter and spark tester to check the spark plug wires and ignition coil.
  • A fuel pressure tester and injector pulser/balance tester, used together to test the fuel injector flow rates.
  • A multimeter, test light, noid light, oscilloscope or other tools to check for wiring issues associated with the sensors, ignition coils and fuel injectors.
  • A vacuum pump, vacuum gauge or smoke machine to rule out the possibility of vacuum leaks.
  • An exhaust backpressure gauge, or pressure transducer to check the engine’s air pumping action and rule out a restricted exhaust system.
  • A compression tester, cylinder leakage tester or borescope to check for internal, mechanical engine problems.

Depending on the situation, there may be more – or less –  tests and tools required, of course. We feel that all of the additional work that comes after “pulling the code” is part of the proper, complete diagnosis, and it’s included whenever you pay us to diagnose a warning light on your vehicle. We hope this insight into what we do every day will help our customers recognize the value in the diagnostic charges that they are billed for. After all, by the time we’re done, we should be able to tell you exactly what your vehicle needs without any guesswork. It’s what we’re known for, and our reputation depends on it!

Buying a Used Vehicle? What to Look For: A Mechanic’s Perspective

Monday, May 19th, 2014

inspectingengine

Depending on your situation, buying a used vehicle can be a very smart decision. New vehicles usually lose as much as 50% of their value over the first couple years, giving savvy shoppers a chance to purchase a “near new” vehicle while letting somebody else take that big depreciation hit. Vehicles are built much better today than in decades past, so even a 10 year old used car should be expected to provide you with many years of very reliable service – providing it has been cared for.

As an auto repair business, we get to see the good, the bad and the ugly of the used car buying process. Sometimes a customer’s new purchase turns out to be a great buy, and sometimes it goes the other way! Based on the problems we see regularly, here are some tips to consider when shopping for a used car:

 

  • Have the vehicle inspected before you buy it. You’d think this would go without saying, but we actually do way more “post-purchase” inspections that pre-purchase checks, and often the customers are less than impressed with the results! A good pre-purchase inspection can arm you with the information you need to make an informed buying decision, and serve as a bargaining chip if the vehicle requires any repairs.
  • Check the maintenance history. This is another obvious one, but often overlooked. The more thorough the owner’s records, the better. A bunch of invoices from one repair business can indicate that the owner has built a relationship with a local company and is dedicated to looking after their car. Look for patterns such as a future repair being recommended on one invoice, and then being completed on a later one – did the owner follow through with the shop’s recommendations? A stack of invoices from 10 different shops can indicate that the owner might be a “price shopper” and less concerned with quality; and certain services may have been neglected or overlooked.
  • Have a mechanic look through the maintenance records. Automotive service invoices are sometimes difficult to decipher, and can contain mechanical jargon that’s hard to understand. Someone in our field can help you understand exactly what services were performed on these invoices, and can pick up on certain issues you might overlook, such as if the wrong fluids were used, etc.
  • Find out who was driving the vehicle, and why they are selling it. The best used vehicles come from people who purchase a vehicle for their own personal use and drive it for several years before selling because the vehicle doesn’t fit their needs anymore. Rental and company-owned vehicles are often operated by many different drivers, none of whom are too concerned with the vehicle’s well-being! Also, be wary of backyard “car-flippers”; these are people who purchase vehicles in order to repair them and sell them later for a profit. These people are usually operating without an AMVIC license and the vehicles often exhibit substandard repairs, slapped together with used or cheap parts.
  • Take the vehicle for a thorough test drive. Don’t feel guilty about asking for a proper, longer test drive! If the seller really wants to sell you the car, they’ll agree to it. Ask to be able to start the engine cold, after it has been sitting for many hours, or preferably overnight. Many abnormal engine noises and other problems will only show up when the engine is cold. Following the cold start, drive the vehicle under different speeds and conditions for at least 20 minutes in order to fully warm it up. This will allow you to adjust to the vehicle and pick up on things you wouldn’t have noticed on a quick “around the block” road test. It will also allow you to catch any problems that only show up once the car is hot.
  • Look for little warning signs. There are sometimes warning signs that can tip you off about a vehicle that hasn’t been cared for that well. This can include broken or missing interior trim; features and options that don’t work; a bunch of bulbs burnt out; even tires that haven’t been rotated (quite worn on the front, and like new on the rear; or vice versa). Is the “change oil” light on, or is the vehicle way past the mileage on the reminder sticker? While these aren’t big issues by themselves, they can be signs that the owner hasn’t taken pride in the vehicle, or their mechanic hasn’t been doing a great job helping them keep the car in prime condition.
  • Be wary of vehicles that were in a recent collision. Even after a body shop restores a damaged vehicle to like-new condition on the outside, there is sometimes concealed damage which doesn’t show itself right away. This could be something like a punctured air conditioning compressor tucked behind that brand new bumper, which you don’t find out about until summer. Even worse, a lifetime of strange electrical problems can be caused by crushed or chafed wiring harnesses hidden behind new body panels.

 

In a future post, we’ll dive into other aspects of the used car buying process, like “Is a Carfax report worth it?” and “Should you buy an extended warranty?” so stay tuned!