I know that most folks really don’t want to know the technical details of their car repairs: let’s face it, cars are very complex and beyond the understanding of most people. And this is fine, however as a shop owner and technician I think a little bit of insight into what the technician has to do to repair and service your car goes a long way to create a sense of value for you.

With that in mind I’ve included a picture of a wiring diagram from a recent diagnosis on a 2006 Mercedes. The window washer wasn’t working when you push the washer button. No sounds were heard so it was obvious that the pump wasn’t running and the concern was electrical: either the pump was dead or it was not receiving power when it was supposed to.

This wiring diagram shows the complete wiper and washer system and what is amazing to note is, in addition to the numerous wires, there are 6 computers involved with this system. Now before we get too overwhelmed by that complexity, because as technicians we could, we need to develop a diagnostic strategy. Fortunately in this case the best place to start and not involve all the complex electronics is at the washer pump itself: we access the pump and test the wiring to the pump. While doing this we found that power and ground was good which confirmed that all other items in the circuit, including those 6 computers were good and the pump was bad.

Wiring diagram: Note the computers which are circled in red. The washer pump is on the bottom left of the diagram

Diagnosing this concern was quite simple but at some time one of these computers may malfunction and diagnosis will be far more complex and expensive.

Now before you get all smug and say “I don’t have a Mercedes, I drive a Chevy”. Rest assured that things are almost as complicated: while there may not be 6 computers there is at least one, if not more.

While it may seem overly complicated to have all of these computers, and in some cases I believe it is, there are specific reasons for it. First, the number of wires in the car is reduced substantially and second, functions in the car are easily integrated. An example is your door lock system flashing the lights and tooting the horn when locking or unlocking your door with the key fob. With that basic system in place adding an alarm function is easy. This is a simple example of the many ways that your vehicle’s electronics coordinate many functions.

There you have a little insight into the realm of the Auto Service Technician and the complex tasks that we must perform in order to keep your car in great shape.

When it’s possible and we can be certain of doing a lasting repair we will choose to repair something instead of replacing it. Here’s an example from a recent repair on a 2002 Acura MDX. Our client’s concern was that the right headlamps were not working. During our diagnosis we found that the low beam bulb just installed by the client was defective and worked fine after we put in one of our own. The right high beam however did not work and I also noted that the DRL lamp on the dash was on and that the DRLs (Daytime Running Lamps) did not work. Diagnostic test found that these concerns were caused by a defective DRL module. We were able to open up the module and while inspecting inside found a couple of dried up solder joints connecting a relay to the circuit board.

DRL circuit board: the yellow arrows point to the broken solder joints which only require resoldering to restore the DRL module to full operation

At this point repairs could go 2 ways: 1, replace the DRL module, or 2, solder the bad connections. Our client opted for the 2^nd option and saved over $100. That’s just one way that we save you money whenever we have the option.

Diesel engines and diesel fuel injectors have changed remarkably in the past decade: gone are the rattly, smoky, stinky, low performance engines from the past.

Modern Diesel Fuel Injectors and Engines

Today we have the modern diesel: powerful and quick to accelerate, smoke free and quiet, with the added benefit of low exhaust emissions, and often times amazing fuel efficiency. 60+ mpg in a VW Jetta TDI is common!

There have been many changes that have allowed this remarkable transformation and one of the major contributors is the fuel injector which has undergone an enormous revolution.

Dodge Cummins Diesel Injectors, old & new: The old mechanical injector is on the top and the new style, common rail injector on bottom

Diesel Fuel Injectors Deliver a Fine Spray of Fuel Under Very High Pressure.

On older engines all components within the injector were mechanical. The injection pump, again a purely mechanical device, precisely controlled the quantity of fuel to be injected.

Fast forward to today: the fuel injector’s controls are now electronic and the mechanical injection pump is gone. In its place is the common rail system. What common rail means is that all fuel injectors get their fuel from the same fuel rail under the same pressure. There a two types of common rail system: one with very high fuel pressure and another with low pressure fuel that uses high pressure engine oil to boost fuel to a very high pressure inside the injector.

While solenoids have been used inside the injectors the pinnacle of modern fuel injector technology is the piezoelectric crystal which, when electrically energized minutely changes the shape of the crystal and switches a small fuel chamber on and off. The on/off flow in the small fuel chamber triggers the top of the fuel injector to open and close and in turn spray fuel into the engine. The miracle of this injector is that it allows precise injection control to the millisecond.

Old diesels received only one shot of fuel during their combustion stroke while modern diesels receive several injections at precisely timed intervals and this has created the amazing engines that we have today. Through these timed injections more power is produced and the knocking sound, so common to diesel engines is virtually eliminated.

How do modern injectors fair for reliability?

Well they have their concerns and quite honestly many are problematic. However much of this may be due to recent changes in diesel fuel refining.

In the late 2000s, ultra low sulfur diesel fuels were introduced in North America. Minimal sulfur emission is great for the environment but unfortunately for the diesel fuel injector, the refining process removes some lubricants that are crucial to long injector life. All diesel engines built 2008 and newer have upgraded injectors but those prior will likely suffer early failures.

Injector failures show up in a number of ways such as long crank times or no starts, smoky exhaust (usually black) and rough running.

Poor maintenance can also affect injector life

With the expensive components in a diesel engine, performing oil and filter changes and fuel filter changes at or before the prescribed interval is essential.

Replacing modern injectors is very expensive, typically costing several hundred dollars per unit along with a very labour intensive operation. So you may wonder, what can I do to prolong the life of my injectors and avoid expensive repairs? There are several things:

First is to keep up your maintenance:

Change engine oil and filter regularly and replace fuel filters regularly.

Second is to add a lubricity additive to your fuel:

These additives will restore the lubricants missing from modern ultra low sulfur diesel and prolong the life of your injectors. While there is addition cost, some of these additives will boost the cetane rating of your fuel and pay for themselves with improved fuel mileage and performance.

Using the right fuel additive and performing proper maintenance will maximize your diesel fuel injector’s life: it’s a no-brainer that will save you thousands of dollars.

That orange lamp on your dash that either shows a picture of an engine or says “check engine” is often misunderstood so here is the check engine lamp demystified.

• This light is there to indicate a malfunction with your vehicle’s engine management system.
• On any vehicle 1996 and newer it will illuminate for any concern that will cause excessive vehicle emissions.
• Many times when the light illuminates you will feel no difference in the way your vehicle runs. This is because many emission reduction systems on your vehicle do not affect the engine’s performance. At times when you don’t feel diminished performance it is because your powertrain computer is compensating for the defect and readjusting things so that performance feels normal.
• As with all amber lights on your dash, an illuminated check engine lamp indicates a concern that needs to be addressed but it is not crucial that it be done immediately (unlike your red oil lamp which, should it illuminate means stop your engine NOW).
• If your check engine lamp is blinking have repairs conducted as soon as possible. The blinking check engine lamp indicates a catalytic converter damaging engine misfire. Usually when the lamp blinks this will be accompanied by a rough running engine. Failure to repair the misfire quickly will damage your catalytic converters and cost you a lot of extra money.
• If you go to AirCare with your check engine lamp on and your car is 1998 and newer you will fail the test! So save money and have it fixed first.
• When your check engine lamp comes on it is rarely associated with low engine oil or low coolant. It is however wise to check these fluids just in case they are low.

The Check Engine Light: some lights show only the orange outline whereas others show only the letters

What if my engine runs fine and I just leave the check engine lamp? If your lamp is on it is most important to get a diagnosis as soon as possible. Some items are more critical to repair than others as is the case with engine misfires. Other items can be left if your budget doesn’t allow for repairs today but it is best to know the urgency and the consequence of not doing the repairs now.

The best way to save money on car repairs is simple:

It’s with routine maintenance.

Routine maintenance means that at specific time intervals, based on how much you drive, you have your car serviced following a maintenance schedule.

The very minimum schedule that should be followed is the manufacturer’s maintenance schedule. Following this schedule will make certain that you fulfill all of your requirements should you have a warranty claim. Some manufacturer’s schedules are more thorough than others and a good maintenance shop will review the schedule and make additional suggestions to help further maintain your vehicle.

It is almost always cheaper to do Car Repairs before they break. Here are a few examples:

One oil change every 6,000 kilometers for 60,000 Km equals 10 oil changes and a total cost of around $600.00. A lack of oil changes causing a blown engine is $4,000.00 and could easily cost double that based on the type car that you drive.

An average, thorough timing belt replacement (with water pump, pulleys and oil seals) can range from $1,000.00 to $1,500.00. Neglecting it and letting the belt break puts you back in the $4,000.00 and probably far more expensive price range.

Replacing brakes before they start grinding could be as low in cost as $300.00 but if left until grinding could easily run you $700.00 or far more.

Other Tangible costs:
• Towing
• Lost work hours
• Arranging transportation to and from the Repair Shop

Intangible costs:
• The stress of readjusting your schedule
• Being without your car when you need it

Through routine maintenance you will know the condition and lifespan of many of your vehicle’s parts. At specific intervals critical services like oil changes and fluid flushes will be done extending the life of your vehicle.

Will routine maintenance eliminate all surprises? Unfortunately it will not, but it substantially increases your odds of trouble free driving.

1 Page of a maintenance schedule for 2005 Ford F350 6.0L Diesel

So there is your key to save money on car repairs: Maintenance, Maintenance, Maintenance!