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Info, info, info!

Written by Randy Gerdin on May 1, 2017

Last week, we had one of our regular clients drop off his late-model pick-up truck. He said his main concern was that the vehicle started okay in the morning, when the engine was cold, but started really hard after the engine was warmed up. Of course, our brain immediately starts thinking of the possibilities. Is it a fuel pressure problem? Is the truck loosing spark when the engine is warm? Is the computer failing to operate the injectors properly when warmed up? All these are possibilities for this symptom. As he was walking out the door he said, “I almost forgot, could you please check out why the temperature gauge is not reading?” So not trying to jump to any conclusion, we wrote up the repair order. “Hard starting after engine is warmed up and inspect system as to why the temperature gauge is not working.”

The next day, we began work on the truck. We verified that it started up fine when cold and we test-drove the truck about 10 miles. We shut off the truck and had to crank over the engine numerous times before it would restart. We also verified that the temperature gauge was not working. The technician started by checking the fuel pressure, spark, etc., and all the basics were there. We then hooked up our factory scanner. We found that the computer sensor was relaying an engine temperature of only 70 degrees. Clearly the engine was much hotter, around 200 degrees. Further circuit testing found that the engine coolant temperature sensor was defective and was sending inaccurate information to the computer, and the computer was not providing the proper amount of fuel to the engine. In fact, it was over fueling the engine. This was also the cause of the engine temperature gauge not reading properly. This is the same sensor that informs the dash gauge of the engine temperature. The computer uses this temperature information to calculate the fuel and timing needed to run the engine and time the transmission at the various engine temperatures.

We often see a vehicle come in with the check engine light on where the customer’s concern is they have poor heat coming out of the heater during the winter. Often, we find that the engine coolant temperature is too low, causing poor heat. The engine computer monitors the temperature continuously to make the proper fuel and timing adjustments. In many of these cases, we find the engine thermostat is not controlling properly or is stuck open, not letting the engine reach its normal operating temperature. The point is, one thing affects another. You may think you have two problems, but perhaps you only have one issue.

We often see vehicles come in running poorly and we find 5-6 diagnostic codes stored in the computer’s memory. Often, there is only one issue that may trigger all of these additional codes. As with many things, information is power. We would rather have more information than we actually need than less. In many cases, we end up having to contact the driver to ask a question that may seem unrelated to their original concern. We have some clients who actually will write out or type out a list of their concerns along with the symptoms. This can save so much diagnostic time for us and in turn will cost the client less. Time is money, as they say.
After years of working with vehicles, we have gotten pretty good at asking the right questions, but sometimes we still need more information. I cannot count the number of times that I have thought, “I wish the driver would have told me that in the beginning”. In our fast pace world, I know that folks sometimes just forget to mention symptoms or concern. It seems that people are always in a hurry.

From the repair shop’s perspective, we would rather spend a bit more time up front and get the complete story. This way, we do not have to try to contact the owner for more information. Also, it is important on the day your vehicle is in for service you are available to be contacted. We use the phone, of course, as well as e-mail and texting in order to communicate with our clients. The worst thing is needing to know more information and you are stuck until you can get in contact with the client. I Hate When That Happens!

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