I can remember back in the late 1960s, my wife and I were taking a cross-country trip in our Toyota car. I needed a little service on the car, so I stopped at a small independent shop. I was told they didn’t work on any of that “import junk.”
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Opening the hood of my Toyota wasn’t much different than opening the hood of my Ford pickup. Both engines had a distributor with ignition points, both engines had a carburetor sitting on top of them, there was a mechanical fuel pump on the side of each engine and a manual transmission fastened between the engine and differential, which was mounted in the rear of the vehicle. Was the problem the animosity of the import vehicle coming to the shop, since yes, it was different than the Ford vehicles because it used a totally different set of tools to turn the nuts and bolts that held it together? Maybe the problem with the Toyota was this was some kind of new kid on the block and it was just plain different. Or was it the starting of the technology change that was scaring the shop owner away from bringing my Toyota into their shop?
Any time I am in a different part of the country, I like to drive around to see what the country is like and especially to check out other auto repair shops. Many times I see “foreign and domestic” on the sign along with the shop name. What does this mean? Is it saying that the shop is not afraid of any vehicle coming to the shop no matter its origin? Does it mean the shop is properly equipped to work on any vehicle on the road, no matter if it was built in North America, Asia or Europe, or is it just saying, “Bring it in and we’ll give it a shot?” Twenty years ago I would take in heavy trucks, cars, light trucks, tractors and farm machinery, without ever the thought of being properly equipped to complete the repair to the machine. Today, I am a little more selective on the jobs I take in. There are some jobs that I just don’t feel qualified to attempt. Maybe this was because 20 years ago things were simpler. There were no computers involved in most of the things that came to my shop, and the problems that I fixed were purely mechanical or electrical in nature. Whatever the reason was, today I have no problem turning some jobs away from the shop since today I am not equipped to work on everything.
Quite often I read articles where shop owners are advised to specialize in one or a few different makes of vehicles. Over the years I have known several different shop owners that did this and were very successful. I also remember working with my wife while organizing training events in our local area. My wife spent a lot of time on the phone calling the different shops and telling them about the training. At times I would get a kick out of the excuses that were used to not attend the training. The best one that sticks in my mind was, “We only work on Ford vehicles in our shop and our tech knows everything there is to know about Ford vehicles.” The class that was being offered was a class on Mazda fuel systems. I thought this rather comical, since this shop worked on a lot of Mazda vehicles and thinking back, three or four years later this shop was out of business. Technology kept marching on and left this shop behind.
So what does all this have to do with domestic vehicles? The domestic vehicle of today has components that are manufactured in many different countries. Some of the domestic branded vehicles are not even assembled in North America. On the flip side, many of the import vehicles have parts that are made in many different countries but many of these vehicles are assembled in factories right here in the U.S. and Canada.
Looking back several years, I guess my view of the “domestic vehicle” has changed. On the outside the vehicle of today is truly a global vehicle no matter where they are built but on the inside; things can be a lot different. For most shops here is where the kink is. With so many different types of electronic systems on the different makes of vehicles, the cost of letting everything with wheels come through the doors can be quite daunting.
No matter the vehicle origin, is it profitable to stay up to date with both tooling and training to do everything on all vehicles? If we stick with the emission related end of the vehicle, most problems can be taken care of with global OBDII technology but once we step over the line to body control, antilock brakes and airbag work we delve into a whole new world of adventure. Very few of these systems are common between makes and some are not even common between different models and years of the vehicle. Is it profitable to tool up for complete coverage for these types of jobs?
My shop is remotely located in small town America, one of those small out of the way sleepy towns, a town where farm tractors are as common on Main Street as are cars. I have been in business here for 20 years and have seen many changes to our industry. Along with these changes I have had to make many changes to be able to stay in business, including in the diagnostic tooling and training department. The world of problem diagnosis fascinates me, so I have moved my business in that direction. Electrical and drivability problem analysis is what I love to do. This work brings all kinds of problems to the shop, some foreign, some domestic. The last few weeks have seen Ford (Mazda), Mercury (Nissan), Pontiac (Toyota) and Chevrolet (Isuzu), all with problems, all needing some problem analysis before any more work can be done.
The first problem vehicle is a 2000 F250 powered with the 7.3 Powerstroke diesel engine. The complaint is the engine will not start in cold weather if the electric engine heater is not plugged in and the engine does not have as much power as it used to have. Looking at the odometer, I found it had 349,000 miles registered.
When I start on a problem like this, I first want to know if the batteries are producing enough power to turn the engine fast enough, are the glow plugs working properly and are the fuel injectors capable of injecting fuel into the combustion chambers. The first test is to hook up a scan tool, pull any stored codes that might be present and then do the Key On Engine Off (KOEO) electrical injector buzz test. This will verify the electrical integrity of the injectors, the capability of the injector driver module to pulse the injectors and by listening, the technician can hear the injectors being operated.
The next test is to verify proper glow plug operation, relative compression and proper cranking voltage. By hooking a current probe around the power feed wire to the glow plug relay, a high amp current probe around one negative battery cable and hooking a voltage probe to one battery, these three things can be tested with a labscope all at the same time. With this one simple test, I will have enough information to either stop here, or move on.
When the key is turned on and the glow plugs come on, I want to see 180 to 192 amps of current draw to the glow plugs. When the engine is cranked, I will look at the minimum inrush voltage (the lowest voltage when the starter contacts close). This inrush voltage should not fall below 8.5 volts (see related article http://www.searchautoparts.com/motorage/motor-age-garage/starting-charging-system-scope-analysis ). The relative compression test will tell me if the engine has any cylinders with low compression. The KOEO electrical buzz test found injectors Nos. 1, 5 and 8 did not buzz. Because there were no electrical circuit codes stored, this tells me that three of the fuel injectors have a problem with the hydraulic part of the injector.
Now to test the glow plugs and batteries. With the labscope hooked to the glow plug feed wire, one battery negative cable and battery voltage, the key is turned to the run position for a few seconds, then the engine cranked. The glow plug and battery test proved out fine. Now I have a good direction about the low power and hard start problem, I suspect this engine needs a set of fuel injectors.
There is one more test that needs to be done: the cylinder contribution test. The engine was started and brought up to operating temperature and the scan tool was used to perform the cylinder contribution test. This test stored a diagnostic trouble code (DTC) for cylinder 8 contribution. While the engine was running, there is an audible misfire from one cylinder.
The results of the testing found there were no problems with the batteries or the glow plugs. The hard start problem is caused by the hydraulic portion of the fuel injectors being stuck and not allowing the injectors to work. By having the electric engine heater plugged in, the injectors will stay warm and the engine will start. There is a Ford term for this problem. This is known as “stiction” and was fixed with eight new fuel injectors.
The next vehicle is a 1999 Nissan Quest (this same vehicle could be badged as a Mercury Villager). The odometer shows 149,000 miles, the engine is the 3.3 liter V6 with an automatic transmission. This vehicle came to the shop with an overheating problem. When the vehicle was driven to the shop, the electric cooling fans were running on high speed and blowing cold air through the radiator. Removing the radiator cap found the radiator full of coolant. Reaching into the passenger compartment, I could feel the heater blowing warm air. Checking the coolant temp gauge found the needle was in the “hot” position.
This tells me that the water pump is pumping coolant, but it is not circulating through the radiator. The problem lies with the stuck thermostat. The thermostat was removed and tested and found to be stuck in the closed position. (I always love it when I am able to find the problem this easy.) A new thermostat was fitted to the engine and an airlift tool was used to vacuum fill the cooling system. The engine was started and brought to operating temperature and then the cooling system tested for combustion gasses. This is something that I do on any engine that has been overheated.
In this case, I used the blue block tester fluid with no problems found. Keep in mind that any test that we do is only telling us the condition of the problem at the time of testing. The vehicle was test driven and the engine stayed cool during the test drive. During the test drive, though, the heater quit putting out hot air. Something is still wrong. I have fixed one problem, but I don’t think I have fixed the root problem.
Back at the shop with the engine idling, the coolant temperature was still climbing to “hot” unless the engine speed was increased to 2,500 rpm. Another combustion leakage test was performed. This time I used one of my more “high tech” methods, the balloon test. I fastened a latex glove around the radiator filler neck and then started the engine. After running the engine at 2,500 rpm for about five minutes the glove began to inflate quickly and fill with coolant. The engine has a combustion leak into the cooling system that will only happen once in a while.
The test with the blue block tester fluid missed the problem, but by using the rubber glove and trapping everything in the cooling system, and exercising a little patience, I caught the problem as it happened. The cylinder heads were removed from the engine to find damage to the fire rings on some of the cylinders. During the tear down process, I also noticed the cylinder head bolts were not very tight. Since this engine is a rebuilt engine with only 30,000 miles, I wonder if the cylinder heads were installed properly.
Two problem vehicles, one domestic and one “foreign.” Well, the foreign car might just as well have been a domestic all things considered. Perhaps we should reconsider our use of the word “foreign,” instead using it to describe cars we are as of yet unfamiliar with. Time for a little training?
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