Oils leaks of various sizes creep up in Chevys
The only used one we could find was held by a savvy salvage yard guy up near Montgomery, Ala., who wouldn't let go of his precious used one for less than $150.
Surely there had to be a viable way to take care of this problem! I saw it as a challenge, and embraced the project.
Sam, our local parts supplier, had the wherewithal to repair power steering lines, so we sent the hose over there with the idea he could replace the rubber part of the assembly using ferrules and fittings. Well, he hit a stump, too. All his fittings were 10 mm, and the metal part of this line was 11 mm. Thanks a lot!Sam is a nice fellow, but he isn't a technician and he's even less of an engineer, and he mistakenly thought he could grind the tube down to 10 mm and make his trusty universal fittings work. He attempted it using a bench grinder, with predictable egg-shaped results, and now the metal portions of the line were almost too short to use. Can anybody say "disaster?"
We were in a pickle. This was stressing me out. There was a chance we might be able to salvage the old line, but it would take some engineering. Sam's idea was actually sound (resizing the line to fit the ferrules), but it would have to be done a different way.With the lines back at my shop, I took some 100 grit crocus cloth and worked the end of that 11 mm Lexus power steering pipe down to a nice10 mm tube that was compatible with the 10 mm ferrules. The line was beefy enough that the miniscule reduction in wall thickness wasn't an issue. He felt so bad about the whole deal that he let us have the new hose material and the fittings for free, and the lucky Lexus owner squeezed by for a very small charge.
We had previously found a faulty PCM that was holding an injector open on that same car, and with those two repairs, we had effectively earned his trust. Thus he called me when his mother's Blazer developed engine trouble.The Knocking S10 Blazer
"The engine in my mom's '96 Blazer needs replacing," the Lexus owner told me on the phone, calling from Mississippi. I wondered how he came to that conclusion. I've seen people respond to milky engine oil by replacing head gaskets or rebuilding GM V6 engines when an intake gasket would have done the job, so rather than engaging in a lengthy conversation over a scratchy cell phone connection, I told him to have the Blazer dropped off at the shop, and the next day it appeared on a rollback.It was knocking like blue blazes – he was right. This was a catastrophic failure. The dipstick showed plenty of nice, clean oil; somebody had run it very low and didn't add any lube until it started knocking. That's generally how those situations go. The number six rod had starved for oil first and hammered its bearing to oblivion.
The salvage yard guy down the road had a low mileage used 4.3L for a very reasonable price. The engine swap was under way.
Vehicle Inspections
Three of our high mileage Chevy pickups (state vehicles that belong to the college) were leaking engine oil from the bell housing area, and since most of the students are learning about transmissions, it would be pretty slick to have these oil leaks handled by students, since one of the NATEF tasks involves transmission R&R.Truck No. 1 was a 2000 model with a 5.3L engine, and it had a fairly considerable oil leak, so we did it first. I gave the job to Bert, and he got the transmission out and the flywheel off so we could explore the source of the leak. Our plan was to replace the rear main engine oil seal and the transmission torque converter seal while we were in there, but it turned out that the rear main seal wasn't leaking after all. The lube oil leak was oozing out past the pan gasket, and as I examined the leak area, I realized why the leak was happening. More about that in a minute.
After we removed that nice little under-the-engine cross member and the oil pan (we still had to remove mount bolts and jack one side of the engine up for the pan to clear), we recognized the fact that the oil filter head is actually a part of the engine oil pan (Chrysler's 2.7L is built pretty much the same way) and it's at the rear where the oil filter usually is on a small block GM V8. This $40 oil pan gasket is fairly robust, a metal skeleton with silicone type material forming the seal, and the metal part of the gasket is actually riveted to the oil pan. The part of the gasket at the driver side rear corner that was supposed to contain the pressurized lube oil feed to and from the filter had given way and the lube oil leak naturally made its way into the bell housing to drip out at the lowest point, thus my inaccurate diagnosis.Several years ago, I wrote about a 1998 Dodge Stratus with a severe oil leak that had been diagnosed by a shop in another city as a rear main engine oil seal. Our black light-and-dye test revealed a leaking head gasket that had failed much in the same way as this 5.3L Chevy oil pan. Overhead cam engines all have a pressurized lube oil passage through the head gasket, and oil leaks like that are easy to misdiagnose.
With the gaskets and seals replaced, that one was back on the job, and Chevy pickup No. 2 was waiting in line with an oil leak that was even worse than the one Bert handled.
Greasy 4.3L
The next oil leak we went after was coming from the same area, only it was a whole lot worse, and the 4.3L was a lot more akin to older Chevy engines than the 5.3L. A different group of students (Ethan and Antwain) jerked the transmission out of truck number two, removed the flywheel, and found the oil pan gasket leaking on that one, too.GM had opted for that silver RTV on these engines, and that stuff tends to lose its sealing ability on some high mileage vehicles. Interestingly, I remember GM using RTV for valve cover gaskets all the way back into the early seventies and we still use it to seal differential covers with almost no issues. This oil pan got one of those pretty blue Fel Pro oil pan replacement gaskets instead of RTV.
Blazer Oil Panhandling
David, who was trying to stuff the engine into that 1996 Blazer, had transferred the accessories and the remote oil filter piping, installed new engine mounts (both mounts on both engines were broken) and was having a devil of a time getting the engine and the transmission lined up in the truck. Some of you Chevy experts are already smiling, aren't you?One More Blazer
Jamie is a student whose grandfather drives a 1998 Blazer that developed a nasty misfire and some destructive sounding backfires to go with it. The distributor cap was only a few weeks old, so the spark plugs and wires were replaced, but to no avail.We scoped the ignition system and saw ragged downsloping firing lines on cylinders one and two, along with some backfiring. The firing order was verified and found to be correct. Disengaging the No. 1 wire from the cap actually made the engine run better (older guys like me can't help but remember how carbon tracks would act like produce this symptom on those now-ancient phenolic distributor caps). That felt good too, and I needed that after misdiagnosing those oil leaks.
Richard McCuistian is an ASE-certified Master Auto Technician and was a professional mechanic for more than 25 years. Richard is an auto mechanics instructor at LBW Community College/MacArthur Campus in Opp, Ala. E-mail Richard at [email protected]
