Cam seals or valve seals?

Heads, valves, pistons, rods, crankshaft, etc...

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entirelyturbo
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Cam seals or valve seals?

Post by entirelyturbo »

Okay, I'm got some things I need to figure out here.

We all remember how distraught I was when I found out I was burning oil. So I switched to pure dino oil to try to stop it. During the couple weeks in between the last oil change and when I parked it to do the clutch fork, I didn't lose hardly a drop of oil, through many different types of driving.

However, I'm not sure I'm out of the woods yet.

I took off every last thing exhaust related to do the tranny drop, and I found something quite puzzling on my exhaust manifolds. The manifold-to-head mating surface on the driver's side of the manifold is all black and sooty with oil. The passenger side has no such residue on it.

Now, I have some oil on the bottom part of my driver's head, surrounding the manifold and what also appears to be leaking out behind the timing cover, by the cam seal :? (I knew I shoulda done them when I did my timing belt :evil: )...

Which of these two "possibilities" (both are kinda off the wall) do you think is correct?

1) The cam seal is leaking and the oil running back across the head is somehow making its way through the manifold gasket and getting burned inside and coming out my tailpipe. It appears that only the driver's cam seal is leaking.

2) The valve seals on only one head are letting oil through. I'm also guessing that the oil is not completely combusting and some oil spray is leaking out through the gaskets and getting the residue I'm finding all over the bottom of my head.

Both would explain the sooty substance on the mating surface of the manifold.

I find both to be strange, because oil seeping through the manifold gaskets seems stretchy, but only the driver's head valve seals also seems kinda weird to me...

I am really thinking about this, because I want to properly stop the oil leaking into the exhaust before I fit a set of new manifolds on it and ruin another good catalytic convertor. And I'm trying to make an almost 14-year-old car leak no oil :roll:

Thoughts? Comments?
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Post by magicmike »

are you saying that oil is getting into the exhaust manifold? if so that means your rings are going. if not then I dont know what to tell you.

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Post by entirelyturbo »

It's not the rings. I tested the compression about a year ago and it was in the 180-190 range for all 4 cylinders. The engine runs magnificently.

So, eliminating the rings, the only other common reason would be valve guide seals. But what I'm saying is I find it difficult for only one head to have leaky seals, while the other's seals are tight...
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Post by evolutionmovement »

The exhaust should be sooty to some degree from fuel... Did you use penetrating oil to get the manifold bolts off? Maybe it worked it's way between the gasket? Otherwise, I'll go with the exhaust valve guides as a possible culprit. Intake would burm the oil off in the combustion chamber. Maybe it's just one or two of them, not the whole head's worth.

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Post by entirelyturbo »

The inside of the pipe is sooty from fuel. I expected that. It's the gasket seating surface on the manifold that's black and oily/sooty. The driver's side has it, the passenger's doesn't.

It might be wise to check the spark plugs to see if there's any oil deposits on them :?
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Post by THAWA »

just curious why you think it's unusual that only one head has leaky seals?
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Post by entirelyturbo »

I just would think that if the seals in both heads are the same age and in identical conditions all the time, that if one head has leaky seals, then the other probably would too...

I'm not saying I'm right, that's just what would make sense to me... :?
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Post by petridish38 »

subyluvr2212 wrote:It's the gasket seating surface on the manifold that's black and oily/sooty. The driver's side has it, the passenger's doesn't.
It is possible that the cam seal on that side is leaking oil behind the timing belt cover and penetrating the gasket.... i say this because you say that only the gasket seating surface is oily. I don't think it would be likely for oil to make it all the way through the gasket and into the exhaust, but it could be possible for oil to get inside the gasket area....

My cam seal was leaking to the point where the exhaust stud nearest the cam seal was always covered in a good amount of fresh oil.....

Just one possibility :?

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Post by THAWA »

while i see your point, i personaslly dont feel its that improbable. Most people that blow a piston dont destroy all of em. The same is true for compression, it'll be hard to have all 4 cylinders with the same compression after so long/miles but they're under the same conditions all the time. At anyrate, I wouldn't rule it out as somethign to check if you have the money/time
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