'86 DeVille rear main seal

ojaihockey · #1 (**permalink**) 04-24-08, 02:04 PM

'86 - Sedan DeVille - 4.1

I had a minor oil leak as of a couple of weeks ago. I drove home one night and found a line of oil on the driveway were I had come in. Now the car dumps oil every time I turn it on. It looks like it's coming from right beside the driveplate. Is it possible that this is anything other than the rear main seal? I don't think it's the valve cover - there's not any oil much above the bottom of the engine.
If this is the rear seal it sounds like I'm looking at pulling the engine or getting somebody to drop the trans for me? What am I looking at if I pull the engine? I'm pretty good at building stuff and working with my hands, but the most major car project I've ever done was to change a radiator. Roughly how many hours is this likely to take? Are the air conditioning lines going to be a problem?
A local shop said they could drop the trans for about 400 bucks. I don't exactly have an excess of time or money, and I'd kind of like to get the experience myself if I can, so I'm not sure which way I should go.

Thanks

cadillac_al · #2 (**permalink**) 04-25-08, 07:44 PM

I would wipe off the oil as much as possible and see if I could find out exactly where it is coming from. A rear main seal usually doesn't leave a line of oil while you drive. I'm not sure if the 86 has an oil cooler or not but I would look at those hoses first. If it's leaking that much it shouldn't be too hard to find it. I just replaced an oil pan last summer on a Buick that rusted right through.

FrankC · #3 (**permalink**) 04-25-08, 08:30 PM

My 86 Eldorado has oil cooling lines. And one of the O rings on the engine end of one of the lines was leaking. It wouldn't "leave a line" of oil, but it leaked a lot! And it was hard to find because it was at the top of the engine where the oil filter mounts and ran down the back side of the engine. I replaced the pan gasket before realizing where the leak actually was.

still_walkin · #4 (**permalink**) 04-26-08, 05:23 AM

i have the same problem and the local shop told me 800 but it was a foriegn shop and they wasnt fimilar with cadillac so i m going to go for a second opinion but on the other note keep me posted

ojaihockey · #5 (**permalink**) 05-24-08, 12:05 AM

Well guys, I finally took my car in after looking all over it in the hope it wasn't the main seal. The mechanic took the tranny off, and guess what! It wasn't the main seal, it was a crack above it in the block

A local welder tried to weld it today to no avail. It's cracked pretty badly right next to the cam plug. Anybody know where I could get a cheap engine? Or unload a dud car with a real nice interior?

still_walkin · #6 (**permalink**) 05-24-08, 12:11 AM

Try ebay or craigs lit they always have an old deville 4 sell

Edahall · #7 (**permalink**) 05-24-08, 12:49 AM

Quote:

Originally Posted by ojaihockey

Well guys, I finally took my car in after looking all over it in the hope it wasn't the main seal. The mechanic took the tranny off, and guess what! It wasn't the main seal, it was a crack above it in the block

A local welder tried to weld it today to no avail. It's cracked pretty badly right next to the cam plug. Anybody know where I could get a cheap engine? Or unload a dud car with a real nice interior?

Is this car FWD?
I would go to the junkyard or look on craigslist for a 4.5 or 4.9 that has no more than 120k miles. The price should be less than $300 if you're wondering.

ojaihockey · #8 (**permalink**) 05-24-08, 01:23 AM

Yes it is FWD. Can I put on a 4.5 or 4.9 in place of a 4.1?

Edahall · #9 (**permalink**) 05-24-08, 02:24 PM

Quote:

Originally Posted by ojaihockey

Yes it is FWD. Can I put on a 4.5 or 4.9 in place of a 4.1?

Yes

You can do a search find lots of useful information regarding this conversion. The easiest is to install an 88/89 TBI 4.5 that's 155 hp. Should you go with a 200 hp 4.9, it'll require an adjustable FPR to dial in the extra fuel requirements of the larger displacement engine.