Hey all! I recently replaced my intake manifold and in the process replaced the gaskets on the valve covers. They are the original covers and didn't leak before, but now I'm getting leaks and spray from the bolts that hold them down. Not all the bolts, just some.

At high RPM oil is coming out from under the bolts and even out from the breather. I think the breather just needs to be replaced, and the PVC valve in the back always got a little film around it, but the bolts never leaked. Any suggestions? User error?

 

Clean the PCV valve?
Hammer n dolly the flanges flat?
Snugged the bolts down?

 

I'm going to remove the covers and make sure the flanges aren't bent. I'm also going to buy a baffled adapter for the breather. It's currently just a rubber gasket. I'm probably going to buy some hold downs to spread out the tension of the bolts too. I just thought it odd the oil was coming from the bolts themselves and not the underside.

 

The valve cover gasket should abate leaks outta the bolt holes. What I do is adhere the gasket to the valve cover with a very thin smear of RTV, let it set, and then install them. After making sure the flanges are flat of course.

Also, remove the valve cover and check to see that there is a shroud over the PCV port.... all it should suck is air. It should be shielded from the oil splash created by the rocker arm action. Any while there verify that the drain back holes are clear.

Just an interesting tid bit.... some NASCAR race teams allow oil to almost completely fill the valve covers to immerse the valve train and maximize cooling of their dry-sumped system, 9800 RPM engines.

 

Also, as tempting as it is, don't over-tighten the valve cover bolts. I don't recollect the torque but its not very much. Good Luck