after 85 track miles yesterday i noticed this yesterday (the soot on valve cover). the car is driven hard, 24 psi stock turbo tune.



another evo guy said he has the same thing and has no idea where its from. id assume the only real possibility is the exhuaust manifold gasket? i dont really hear the typical tick of a manifold gasket leak. manifold has never been off the car, and i dont believe the stock one is very prone to cracks or anything...


thoughts?

 

Clean it up and try retightning the bolts.

 

they appear nice and rusted.

 

Pull your heat shield off and inspect the manifold all the way to the turbo. Could be the gasket between the manifold and the turbo, but the soot is going under the heat shield.

Or, is your vent in your hood open? Or do you still have the stock louvers there?

 

after that last post i had the thought about the turbo/manifold gasket. unless the previous owner had the turbo off for some reason (which im 99% sure he didnt) it has never been opened, so i would think it would be rare to fail?

hood vent still has stock louvers,, wonder how much suction it actually makes?

 

Gaskets can fail over time, depending on conditions. Remove the heatshield, listen for leaks around the turbo/manifold flanges.

And I don't think the louvers create suction, rather the opposite. I asked because, I thought it was possible something came in through the hood vent, onto your valve cover.