Still leaking after replacing valve cover!?!

[tsi1991awd]

Hey...just bought a 1991 Talon TSI AWD (sorry I keep saying all of this in my threads, but until everyone gets to know me I'd like to be as specific as possible) When I saw the car, there was oil leaking from around the valve cover, on the inner portion around the spark plugs. Now, the guy had the valve cover gaskets and I was there when he replaced them. I thought OK, cool it's good to go now. The old gasket was hard and brittle, so I thought everything was good.

Well, I just saw some smoke coming from the exhaust a little bit ago and then checked under the cover piece for the spark plug wires and there is some oil there....new oil that leaked, because he cleaned it all off before replacing the valve cover when the gaskets were changed.

So, my question is....why? Why does it still leak with the new gaskets? I assume it burned a bit of oil, that's why it smoked. Because it only did it for maybe 5 seconds. I revved it and it didn't do it anymore. Is the valve cover cracked? Because I don't see any cracks in it.

ALSO...I went around the outter edge of the valve cover and made sure the bolts were tight and the top left corner one just keeps spinning...I guess the threads are stripped on the motor end?? Also the one in the middle on the top doesn't turn at all. It just sits loosely in there, and it is the same size as all the other bolts (I removed a different one and tried in that hole)....so what do I do about that?? It doesn't leak from around that edge at all. It just leaks around that spark plug area, so I don't think that would cause that to leak....the bolts around the inner area are snug.

 

[pj91gsx]

you might be able to put a heli coil in the stripped thread after you drill, but you need to keep the shavings from going in the motor. Or you could try just using a tap.

 

[kenamond]

If you have a couple of stripped VC bolts, it might not be sealing very well to the head. Those bolts require VERY little torque (28in-lb or so, but I forget exactly) and are very easy to strip.

When the VC gasket was installed, there are also 4 spark plug well seals and a half-moon seal that goes into the head at the end of the exhaust cam. If you buy a complete valve cover gasket set, it comes with all 6 pieces, but some only come with the big gasket that goes around the outer edge of the VC.

If you're getting oil under the spark plug cover, that's gotta be coming from either a leaking oil cap (it runs down under there, and it is a common place for the VC to leak) or a cracked VC. There is a small drain hole in the front-driver side of the VC that lets anything in that area under the spark plug cover drain out...it's very small and hard to notice, but you can see it if you look. If oil leaks out of that, it can run down to the exhaust manifold flange and burn.

If you pull the spark plug cover off and pull the plug wires and wire guides (mark which plug goes to which cylinder), you should be able to clean out that area really well. While you're at it, take the oil cap off and clean the VC around that area, too. Then drive it for a couple of days and check where the oil is coming from.

You can get new oil caps with a new rubber gasket for pretty cheap, and I've heard that you can get just the rubber gasket for probably even cheaper. The gasket is all you need if that's what's leaking.

Finally, is the burning oil coming up out of the hood or out the exhaust tips? If it's coming from the hood, it's some external leak burning on the exhaust system somewhere. If it's coming from the exhaust tips, it's an internal problem that has nothing to do with a valve cover leak.

 

[nlzn]

The above post pretty much nailed it.. but if oil is coming out of the exhaust it's not the VC as stated. Best advice: (and very cheap and easy to do) do a compression check then a leakdown test and you an narrow that oil burning from worn rings or worn valve seals etc..

Good reference for this: Engine Cylinder Leakage Testing

 

[kenamond]

And here is a compression test page for our cars with compression specs:

http://www.geocities.com/dsmgrrrl/FAQs/compression.htm

 

[kahl23]

It could also be coming through the bolt holes themselves, I had that happen to me once before when I didn't tighten the vc bolts enough.

 

[sleeping95gsx]

they say that every time you take the VC off you have to replace the gasket, so in the process of doing theVC did you take it on and off multiple times after tightening the bolts? Also make sure to clean the surface of the head where the VC sides make contact to make a good seal all around, i use a flat razor. Try appying Some of the hight temp RTV to help with the seal. I ran into what i thought was stripped head fittings/bolts but it ended being that some of the bolts were different sizes! sometimes its the stupid little sh!t that can cause a big problem WTF

 

[ShawnsGarage]

Inspect for cracks around the bolt holes. I had the same problem on my car and then i found a small crack around one of the bolt holes. a small crack can leak alot of oil

 

[tsi1991awd]

Hey, sorry I wasn't clear on my post.

There were 4 round pieces that went around the spark plug tube, one large gasket that went around the valve cover, and one half moon shape. Nothing leaks anywhere except for under that spark plug cover.

I have not pinpointed exactly what happened. The oil is mainly at the bottom edge, probably because the valve cover is slanted a bit. I'm not sure if it's a crack or what it is. I don't see any cracks, but on the other hand I have not looked very well. What I did notice was that when the bolts were tightened, it did made a kind of popping or slight crack type noise, but I thought that it was just the washers.

Maybe it is a couple small cracks or something that I can't really see. But again, as I said, I didn't look very close and inspect what was up.

On the one bolt in the middle, I know for sure I'm going to have to do something about that...retap it or whatever, I don't know at the moment. As far as the one on the corner, it just keeps turning in there. But as I said, that middle one doesn't grab anything...it just slides in there and slides out.



And for the smoke, it came from the muffler. It wasn't for very long. I was thinking the oil leaked into the spark plug tube and it burned or something, but I don't know. It doesn't smoke any other time and hasn't until just that one time. I saw the smoke then revved the engine and some more came out then it stopped. I got out of the car to look and it wasn't doing it. Drove, came back, parked, wasn't smoking. Doesn't smoke from the engine bay...I know it leaks from around the oil filter housing, but I am going to be doing the forward facing filter mount and taking care of that pest.

 

[tsi1991awd]

Does anyone know the thread pitch and size of the bolts for the valve cover by any chance? I'm going to buy new ones and then see what I can do about those two bolt holes that seem stripped. I'm not sure that there is a helicoil for that size of bolt is what I'm trying to get at as well.