A Lesson on What Not To Do in Truck Repair
Every so often, I like to reflect back on strange problems that appeared to make no sense. Upon doing so, I discovered that the problem seemed to defy logic. This is a reflection of how much is actually going on inside an engine.
For instance, there was this late 90’s Chevrolet C7500 that came into our truck repair shop with low oil pressure. The problem had just started the evening before. The truck still had some oil pressure, but it was very low on the dash gauge. So I ran an oil pressure test with a mechanical gauge, and the pressure was in fact much lower than the specified range. The dipstick showed that the pan was full of oil, and there were no leaks.
I pulled the engine oil pan off and, much to my surprise, found the engine oil pickup on the pump nicely wrapped in fully-intact shop towels. This was clearly not what I was expecting to find. How in the world did they get there?
I wondered if the pan had just been off the engine, so I checked the service history. The pan had not been off; however, the truck had been in for leaking intake gaskets a full month before. It started to make sense. Many technicians will place shop towels in the lifter valley while cleaning off the old gasket material. In this particular case, the technician had done just that and then probably was interrupted in some way, leaving the towels in the lifter valley. Somehow, over the next month, those towels made their way through some rather tight spots and spinning engine parts, eventually finding a nice safe spot on the oil pickup screen.
There are a couple of morals to the story. First, you can never be absolutely sure that the cause of a mechanical problem is worn or broken parts. Second, as a technician, most comebacks are the result of hurrying or distractions. Granted, it can be tough to manage both those problems in a busy shop. Nonetheless, having to do the job over is money out of your pocket and damages the customer’s confidence in the shop and you as a technician. It is important to safeguard your valuable reputation, by overcoming those obstacles.