But one peculiar thing about Buck was that whenever we did any work on whatever he was driving, he always found something else wrong that he swore was related to the work we had done. For example, I replaced the Taurus' wiper blades one rainy Monday, and he wheeled back in an hour later to tell me that the wiper motor was making a noise that hadn't been there before I replaced the blades. I found that the wiper motor was worn out and that the noise had nothing to do with my replacing the blades. Ever been there?
Still, there are times when the customer's complaint is legitimate, no matter how seemingly unrelated it may be. One of our problems in this business is that with so many customers trying to get piggy-back freebies, we tend to roll our eyes at complaints of related issues when in reality we should be giving them the benefit of the doubt. For instance, I personally saw one 1977 Cadillac develop radio static immediately after the tires were rotated. Sound ridiculous? As it turned out, the steel-belted tires on that car were older radials that weren't friendly to being cross-rotated, and when they were placed back in their original positions, the radio static was gone. Really, it happened.
How many times have we sent irritated customers down the road unsatisfied with our explanation only to discover later on that their problem was one we had caused after all?THE BLAZER
This customer had a few concerns he wanted checked. To start, the engine was a hard-start, long-cranker, and he had the idea that the fuel pressure regulator needed changing. This Blazer was equipped with one of those delightful central sequential fuel injection (CSFI) systems GM dumped after only a couple of years. At his insistence, I had my students replace the fuel pressure regulator, which was no small feat on that engine. The upper intake had to be removed and with it, a part of the fuel system.I had my doubts as to whether the regulator was the problem, but we replaced it just to satisfy the customer. The fuel pressure wouldn't hold steady at engine shutdown, and I was fairly certain it was the pump rather than the regulator, but it didn't hurt the students to tackle the job.
With the regulator replaced, the fuel pressure decay wasn't any better (not surprising), so I sold him a fuel pump, which handled that hard-start problem. His second complaint was a fairly serious oil leak, which turned out to be a rear main engine oil seal, and I had a different student handle that repair.
The transmission was removed, and the rear main seal was replaced along with the transmission pump seal. It would have been a bad bet not to replace that one as well. After all the work was done, everything seemed fine, the bill was paid, and the Blazer went home.A few days later, the Blazer owner called back to say that his electric rear hatch release no longer worked after we performed our repairs. I have to confess to some eye-rolling here, but I gave the customer the benefit of the doubt and told him to bring the Blazer back so we could have another look.
When I spoke to him, he explained that the key lock cylinder hadn't opened the hatch for years, and so he had been accustomed to opening the hatch with the pushbutton switch up front. We were studying electrical systems at the time, and even if the problem wasn't something we had caused, it would be good for the students to track this one down.
CHECKING THE HATCH ...FROM SCRATCH
First we checked the fuse. Then we followed the circuit to the pushbutton release switch. It had good power and the power would pass through the switch with the button pressed, but there was no activity in the hatch.
Shifting the test light to B+, we checked the circuit feeding the hatch release solenoid and found that there was no ground. Studying that side of the circuit, we found that the hatch release solenoid gets its ground through the neutral safety switch; GM didn't want anyone punching the hatch release button while driving down the road. Think about it: You could lose ice chests, camping equipment, dogs and even kids that way if they're riding back there.To make a long story short, the transmission range sensor connector wasn't properly seated. As unlikely as it may sound, with that connector poorly seated as it was, everything else that went through that switch would work except the hatch release.
MUSTANG WITH A BUZZ
This isn't about a half-drunk horse; I saw a 1996 Mustang that had developed a buzzing noise coming from behind the instrument cluster. I couldn't pinpoint the noise.
The shop foreman noticed that if he held a balled up jacket up at the top of the windshield area, it muted the noise, so we applied masking tape to all the chrome around the windshield, but to no avail. We explained what we had found (or rather hadn't found) to the owner, who told us that he needed the car that afternoon and would bring it back later for further investigation.The owner built some V-shaped aluminum braces and used Velcro to mount them in such a way as to brace the bug shield. The bug shield had been creating an oddball noise that was being telegraphed through the windshield and actually sounded to all of us as if it was coming from behind the speedometer.
ROARER EXPLORER
We had already replaced a faulty transmission solenoid pack on this 2003 Explorer for a harsh transmission shift when we started working on the noise that was coming from the rear differential.
Using a leak and noise detector, we tested the vehicle at road speed, and the results indicated a lot of noise was coming from both the differential and the hub bearings. There wasn't much of a chance that the roaring would telegraph because this differential drives the wheels through a couple of CV axle shafts.
One of my students, Victor, started by doing exploratory surgery on the differential; Ford SUVs of this vintage have had a lot of problems, and this one was no exception: The carrier bearings were badly pitted, and the pinion bearings were showing some of the same. We replaced all the differential bearings.The noise was practically unchanged, however, and further diagnosis led us back to the wheel hubs. After we replaced both wheel hubs, the Explorer could glide down the road exploring very quietly.
I cut the hub bearings apart and found them just as badly pitted as the differential bearings. I could have understood this situation better if all these bearings had been sharing the same oil supply, but they didn't.
Remembering a story about a Mazda RX7 that kept wiping out axle bearings because of a bad battery-to-engine ground, I had Victor check voltage drop and found about 0.5-volt drop between the battery negative post and the engine block.
Disconnecting the battery ground cable from the engine block, we found heavy paint between the cable and the block, so we shined that boss and the terminal. It did away with our voltage drop, but I'm not yet convinced that what we saw there wiped out the bearings. They might have been substandard bearings to begin with. I did some research and found that more than a few of these Explorers have had bad hub bearings to go along with the differential noises so prevalent on this platform.
CONCLUSIONS
What impresses a real-world customer isn't what you and I can take apart and put back together.
Knowledgeable customers just want to know we can figure out what's wrong so they can count on us not to take the whole vehicle apart and put it back together to fix it. They want (and deserve) surgical repairs. Our job is to give them exactly that, as hard as it may be sometimes.
