Bad Smells - Replacing Valve Cover Gasket



A few weeks ago, I diagnosed the bad smells coming from Mr. Toots as a leaking valve cover gasket. There was oil around the valve cover and it was almost certainly dripping on the exhaust gasket and making smells. With that in mind, I ordered 2 cork gaskets from my local auto parts store (Kohlweiss in Redwood City, CA, they are always helpful) and got started on a gasket replacement.


The first problem was getting the valve cover off. The turbo tubing, breather hose, distributor vacuum advance, and hobbes' switches made it very difficult to get the cover off, so I had to remove the breather hose, turbo tubing, and maneuver the vacuum advance out of the way. As a side note, I do not understand how to get the distributor out. Maybe my hands are too big, but the bolt for it is hidden really far back in the compartment and I couldn't figure out a way to get a wrench on it.


One interesting thing was that there are some marks on the valve cover, and grease on the turbo manifold where it comes in contact with the cover. Obviously the designers of this turbo system made a slight miscalculation and covered it up with some grease and sanding.


Here is where the cover has been either sanded down or worn down by the turbo manifold. I'm planning on getting another cover to paint, and I'm not sure if I'm gonna need to make these modifications to it to avoid nasty vibration sounds. We'll cross that bridge when we get there.


Here's where they put the grease on this piece of tubing. I decided to wipe all of this off and replace it with silicon repair tape. It's more visually apparent in the final rebuild, but much less dirty. You can see that in the pictures further down.


Here's a shot of the inside of the head. Timing chain looks awesome, which is a pleasant surprise. One can see where the oil is escaping from the gasket, on the left side and a little bit towards the timing cover. Removing the gasket was simple. One thing I do wonder about is the studs and nuts vs. the bolts. I've seen other cars where the valve cover is held on by only bolts, and my friend's E30 is all studs+nuts. Why is mine a mix of the two?


When we look closer at the top, we see the source of the problem. The timing chain cover is ~0.5mm lower than the face of the head. This means that when the nuts are torqued down evenly, the valve cover isn't parallel with the head and the timing cover, and then we get some sprayout around the gasket. The way I see it, I have a few options:

  1. Buy a new timing cover or head and get them cut to be perfectly coplaner.
  2. Shim the gasket to get them parallel.
  3. Install the new gasket, torque it down, and hope for the best.

I decided to go with number 3, followed by number 2. I have a spare gasket and I'm gonna cut some shims in the coming weeks for the timing chain cover, but I'd like to drive it around in the meantime.


While doing this job, I also noticed the breather system was jacked to hell. I'll cover this in another post. What the heck is this gunk?


Here's the old gasket. Note the Malaga hidden under the horrible black paint.


Here's the new gasket, oiled up and ready for installation.


Cover re-installed. I used the Pelican Parts guide and made sure to do a 2-step torque-down.


And here's the turbo manifold re-installed with silicone rescue tape around the area that contacts the manifold.


Job is done. It smells a lot better now, but there's still some smells when I drive the car hot. Will update once I've made the timing cover shims and hopefully fixed the problem.


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