pita oil leak

[MylilBowTie]

I have tried and tried to track down the oil leak. At first I thought it was the front intake seal and it was leaking but that's been fixed. Last Sunday I replaced the timing chain cover gasket, front seal, water pump, gm 8 in hd balancer got everything back together and it still leaks. I have a felpro one piece oil pan gasket. It leaks where the bottom of the timing chain cover, oil pan gasket and oil pan meet. It only leaks when the engine is running and its enough to keep the front crossmember lip almost full of oil. It doesn't do it as much when it bleeds off whatever amount it needs to witch I assume to be about 1/2-1 qt of oil. It seems like that part of the oil pan gasket isn't thick enough to seal good. I really don't want to hose it down with silicone but may have to so it will stop. Anyone else have the one piece oil pan gasket and this problem?

[79 silverado]

I have the same problem with one of my trucks that has a 327 in it, so I'm interested in teh answer as well.... meanwhile I just been driving it locally topping off the oil, at least it keeps people off the back bumper

[dswancutt]

Did you replace the seal in the timing cover? I know the when my uncle and I changed the timing chain out on my truck, we replaced that and had a bushing put on the harmonic. That might be the source of the leak.

Doug

[swervin ervin]

If I were guessing, I would check the pan and timing cover for straightness. The lip could be bent enough to cause this. I have a Felpro one piece gasket and have never had any leaks. Of course I have a Moroso pan though. If you are sure it's not coming from up higher, I would check the lip on the front of the pan. If it's not round evenly or has a dent, you've probably found the problem.

Good luck with it.

[MylilBowTie]

Im positive that's where the leak is coming from now. I did an oil change even though its already pretty dark again. There isn't any oil that I see anywhere else that its coming from and when it gets driven it spreads the oil all over the oil pan and everywhere else. When I replace the seals and parts I cleaned everything up and painted it best I could. Yes the front seal was replaced in the timing chain cover. The harmonic balancer/dampener is brand new so I didn't need to use the sleeve. The sleeve is for balancers that are worn down a little bit and causing the front seal to leak. So you install the sleeve and that replaces the material that was worn away along with the new front seal and it seals back up.

Does gm still have a replacement timing chain cover? I don't really want a chrome one or way expensive aluminum one.

[Hoods69BadBowTie]

I agree with swervin ervin. I would check this out and see what you find out.
-Later

[Slonaker]

I have the same problem, which ticks me off to no end. I replaced every gasket I could on the engine (including the $75 dealer only pan gasket) a little over a year ago, and now it leaks more than it did before I started. I assumed mine was leaking around my old harmonic balancer, so I was going to get a new one or put a new sleeve on it (it already has one that looked okay to me...). Maybe I need to look at it a little closer.

Slonaker

[DBLSPRT68]

My truck started leaking like crazy, in this area also . It started 2 weeks ago, and slings oil all over the underside, and some down the side of the truck. If I only knew about this when my truck was completely apart! Now, I will have to either pull the motor or try doing it in place . David

[raceman6135]

Here's a long shot: Chevrolet changed the thickness of the front pan-to-timing-cover seal between 1974 and 1975 (the seal got thicker for the 1975-and-newer pans).

Either the parts person sold you the early gasket (Fel-Pro part # OS 34509 T when they should have sold you Fel-Pro part # OS 34510 T), or you've somehow got an early pan on there.

This is assuming that the surfaces were dry, clean and straight when you assembled it with the timing cover gasket change, balancer replacement, et al.

Some guys have good luck and barely have to drop the oil pan when replacing the timing cover: I've always had to undo almost all of the oil pan bolts and drop the front of the oil pan an inch or so before I felt comfortable putting the timing cover back on.

Did you encounter any difficulties when replacing the timing cover gasket?

DJS

[Nolowrider]

I think I have to disagree with you on the seal for the balancer on the timing cover. I think you should have installed it whether or not the balancer is new or not. Also double check the bottom of the timing cover, use some rtv (red). If you tighten the timing cover screws too tigh it will pinch the gasket out. Looking at where the oil is sitting, I think the problem is with the seal. Does the truck smoke when you drive it? The reason I ask this is because, once I didn't put the bottom seal on the timing cover and when I drove it, the oil would leak onto the headers and it would burn off. At Idle there was not enough oil pressure to blow it out. I think your problem will be fixed if you put the balancer seal on.

[Slonaker]

Originally Posted by MylilBowTie

Yes the front seal was replaced in the timing chain cover. The harmonic balancer/dampener is brand new so I didn't need to use the sleeve.

Originally Posted by Nolowrider

I think I have to disagree with you on the seal for the balancer on the timing cover. I think you should have installed it whether or not the balancer is new or not. [snip] I think your problem will be fixed if you put the balancer seal on.

He says he replaced the seal when he installed the new balancer.

Slonaker

[Nolowrider]

Sorry lilBowtie, I must have missed that part. I read it several times and still missed it. My bad. There is only really a few places that it could be comming from and it is all pretty much related to the cover. There is not too much oil that gets into the timing cover. Sounds like you covered everything. Got me stumped. I never got this "sleeve" that you spoke of.

[JustOneTruck]

Scratching my head on this one ......I`ve always always used RTV high temp or something from RTV to hold or place gaskets in place .This small amount of RTV Silicone makes up for any improfections in the mesh or two surfaces meeting together and actually holds the gasket in place from slipping into the pan or out of the pan . And that darn timing chain cover Ive ground off that lip so I could take off the cover with out taking the bottm pan loose . This was so I could advance the cam in even degrees ahead or back.

Like most leaks they always look bad because it just take a few drips to run over things and look wet and thats if its running at idle . Now when your under power and have the wind blowing and the fan from the radiator up front at 55 to 70 mph down the road the oil goes back all over every thing . Im also just going to throw this out to is to make sure you have adequit pcv valve thats working to keep the crank case presure and valve cover presure the same so your not blowing out or putting added presure in the system.

[MylilBowTie]

Its from felpro its a called a sleeve n seal. I asked for a timing chain gasket kit and that's what I got. There really isn't much difference in the two kits other than the small sleeve that goes onto the o.d. of the harmonic balancer/dampener. I could be wrong about the front seal being the same size. I did test fit the new front seal and new balancer and it was tight.

I'm thinking of getting an aftermarket oil pan, is there any way to tell if the front needs the thicker or thinner gasket? I really don't know what year the oil pan on my engine is other than the fact its got the driver side oil tube notch.

[MylilBowTie]

PVC valve is new. I know it is leaking pretty good, I cleaned the area up three or four times and it looks just as bad as it did when I cleaned it up.

Looking at those felpro one piece oil pan gaskets I have the OS 34510T (thicker one).