Merc 5.7 valve covers

[Onexl85]

No matter what I do I can't get the valve cover to stop leaking, I've change the gaskets with oem and also the valve cover with a new own one.
Getting frustrated, any suggestions

 

[pureinsanity]

Might check your pcv system to make sure it is working. If it's not then it can build up to much crank case pressure and push the oil out. Did you use sealer on the gaskets? I know that sounds stupid but I have come across people who are against using it.

 

[nateo]

are you sure it's not leaking from the intake manifold?

 

[pureinsanity]

are you sure it's not leaking from the intake manifold?

Good point or even the oil sending unit. Depending on it coming from the front or rear I guess.

 

[Onexl85]

Defiantly from the valve cover, I put a rag to be sure, never though about the crankcase pressure......if it's too high am I in trouble with the engine?

 

[pureinsanity]

Not necessarily...pull the pcv out of the valve cover with it running and see if it has vacuum pulling through it. If it doesn't then pull the valve out of the hose and check for vacuum. if you have it there then the valve is bad. When you have the valve out of the cover also watch to see if there is a lot of blow-by (smoke) coming from the hole in the valve cover. If the valve checks good and there is a lot of blow-by than we may need to look at the engine, but there are other small things it could be too.

 

[Onexl85]

On this engine, there are no pcv valves. Just two 90 degree angle connectors connecting to a hose up to the flame arrester. There is smoke coming out of the valve cover.
This sucks, the engine runs so good!

 

[nateo]

Is it coming out of the holes somewhere near the angle connectors or near where the gasket is? I have the thick rubber type gaskets on my valve covers, they seem to work well. thin rubber on intake gaskets are fragile though.

 

[Scott Danforth]

center bolt or perimeter?

if perimeter, straighten out the valve cover rails, using a socket and a ball peen hammer as the bolt most likely sucked in the material around the holes.

If center bolt, did you use new grommets under the bolts?

use felpro or rol rubber gaskets.