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Could a small valve cover leak cause a loss of boost on a PCV equipped vehicle?

Iron Indian

New member
I've been dealing with a slight loose of boost lately, i'm only running 10-11 psi when I should be at arounf 14 psi give or take (compared to similar setups). I'm basically Intercooled, Rockered, Headered, etc. I do have a fully fuctional PCV setup with NO valve cover breather.... Here is a post I made on another thead...

Well after remembering an old post on ClubGP years ago I decided to try a different method to find vacuum leaks. I went to my local hardware store, picked up a 3" straight coupler, and a blank end cap. Drilled and tapped a hole for an air line fitting and of course installed a fitting. Installed this piece on my TB, Set my air compressor to somewhere in the 15-20 psi range, and hooked it up.

Immediatly it was leaking from my front valve cover on the bottom. bad enough to spray a little oil. So far that the only leak i've found. I wonder if this was the issue after all? My PCV system is STILL FUNCTIONAL so I don't run a breather. Could I've been losing 2-3 psi in that area this whole time? It wasn't noticable leaking oil before. I'm alittle confused on how the PCV system works because most cars i've been around don't have the setup in the first place. Anyway, I'm wondering if this is my problem or should I look elsewhere. I plan on replacing my PCV and valve cover gasket tomorrow. Any input would be appreciated, thanks!
 


Look elsewhere. The pcv system has nothing to do with that and as you may know the front valve cover has the fresh air inlet side too. Hooking a air hose to the tb really isnt doing any good. I would suggest a cylinder leak down test if you are really worried about it. You need the tool and other than that an air compressor.

What size pulley are you running? Sounds like you have lots of flow mods and i wouldnt be surprised if thats just what it is.
 
Theres more to it than that. I can run anywhere between a 2.7" - 3.0" and still only get 10-11 psi. My motor don't flow that good, not with stock head and cam....
 
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