azarby

Had the car in to the local lube joint this week and they said that the rear of the engine is wet with oil. The said it could be a rear main seal. Is this a common problem and what does it take to fix it. I have an appointment with the local dealer for 1/6 to have them look at it. I have also been using about a quart of oil every 1200-1400 miles is this excessive? The car is a 2001 convertible.

Thanks
Bob

wwashing

This is the first rear main seal leak I've seen reported on this forum and I've been coming here since it began. Replacing the rear main seal calls for removing the engine.

Your oil usage is high. This is usually caused by ring flutter at high rpm under light load. The oil stains could have been caused by spillage during an oil change, if you are lucky? :cheers:

Duck916

Never heard of anyone losing the rear main seal on an LS-1, but I'm sure it happens. I agree with the above--maybe it's just a spill? I'd clean it off really well and see what happens after a day.

As for oil usage, you are a little high and could probably get the new rings for free if you wanted them. If you do have a bad main seal, they could do the rings and the seal at the same time. Do you have an auto or manual trans?

ghost.rider

Actually I did report a rear main seal repair on my 99 6 speed C5 back in March time frame. It had been leaking oil very slightly (1 qt every 2000 miles) since I took delivery and I finally took it in to Criswell before the warranty ran out. I know they had to pull the clutch etc. and unless that requires pulling the motor. I am pretty sure they did not remove the motor. The C5 tech said it is very rare for a C5 to leak oil - that it is a very tight engine - but mine did leak :sad: hasn't leaked a drop since the fix :cool: :yesnod: :lol:

azarby

Duck916

I have an automatic transmission and the car has 15k miles on it. I don't have the ability to put the car up on a rack or on jack stands, so I have to wait to get it to the dealer for them to take a look at it. They also would want to do an oil usage gtest before allowing a ring job. I just hope that it doesn't require an engine teardaown. This 2001 hasn't been too bad reliabilty wise, but has had a lot of body and paint problems. The only mechanical problems so far was an engine missfire problem caused by plugs, wires, coils, bad computer?? They couldn't be sure so they replaced everything associated with the two bad cylinders. Chevrolet bought back my 99 vert because of undiagnosable electrical problems, and I don't want to do that again.

Bob

Duck916

The reason I asked about the transmission is that A4s typically don't use as much oil as MN6s. I also figured a rear main seal might get some oil on the clutch, causing slippage, which would also help you diagnose the problem.

Since you should still be under warranty, it would appear you're gonna have to let the dealer look at it. Take heart, though--it shouldn't be nearly as tough to diagnose as the electrical problems.

Good luck.

Tom Hall

The Cam sensor can leak and run down the back of the engine and look like a rear main leaking. Been there.

Austrian Vette

Same here.

azarby

Well, the verdict is in. The dealer was able to put the car up on the rack today and there is definitely a rear main seal leak. They also said that the oil consumption was due to bad rings and they are going to order out a set of rings and pull the engine for a ring job. That should take care of the main seal at the same time as they have to replace the seal anyhow. I thought that the ring problem was only with teh MN6. I was afraid that this was going to happen. My luck with Corvette reliability is getting pretty bad. Just hope that they can fix it. Don't want to attempt a second buyback. Not sure that they would even do that a second time as they would probably refuse to sell me another Vett.

Bob

:mad :mad :mad :mad :mad :mad :mad :mad :mad :mad :mad

LTC Z06

Put a cam in while it's out. :cool:


[Modified by CPT Z06, 11:34 PM 1/6/2003]

pewterhdtop

Sorry to hear it is the rear main seal! My dealler gave me free oil changes for the first year, I took it in for the first (and only!) one and he told me the front main seal was leaking. Haven't heard of that happening very often either. Had them fix it and no issues.

They did manage to not tighten the oil filter properly, and it leaked oil on the exhaust system, smelled worse than it was. I now do all my own oil changes.

Good luck, I hope it is fixed right and soon! :cheers:

azarby

If it was just a rear seal, i wouldn't be too upset. I don't care for the idea of having the whole engine torn down for a ring job. The last time I had that done was to a 1970 Pontiac Firebird Formula 400. The engine was just never the same after that. I know others have had it done and have been satisfied with the results, but I just don't trust the wrench monkeys they have working on cars nowdays.

Bob

captnorm

About a year ago I had my local dealer repair a rear engine seal oil leak and pan gaskets. Not cheep at $2400. 4 days ago I noticed a small oil puddle (not just a small spot) on my garage floor. I assumed I would have to go back to the dealer prepared for a fight to correct the repair failure. However to my amazement no more oil has appeared on the floor. Where did that oil come from?

helga203

Only thing i can think of is residue.

mmartinez

One of the main causes of oil leaks especially at the rear of the engine is the oil pressure sensor, it starts leaking and runs down the back of the engine.

Napoleon_Tanerite

On a manual car it could be a leaking clutch slave cylinder. They're a VERY common failure point on all LS engines, and will cause a puddle on the ground right about in the same spot as a engine oil leak from the rear of the engine. I'd say step 1 would be to feel for any clutch issues and see if it's losing fluid in the clutch system.

captnorm

This C5 is an automatic. A few more days have passed and still no evidence of an oil leak. Normally for a rear seal repair they pull the whole trans axial and drive shaft back. A big job which is why I paid to have it done. The two piece oil pan is another extra expense.