GM Repair Problems? Ask GM Repair Expert Now.
can you tell me the make and model of the vehicle involved?
there should be a couple of breather paths on the engine
1 low pressure route for when the engine is off boost and a 2nd route for when its on boost
there should be a combination of pressure relief and 1 way valves to prevent boost pressure entering the crankcase
the boost pressure line will have a 1 way valve between the cam cover and inlet manifold to prevent flow in
so I'd say its likely that the 1 way valve is faulty or stuck
I think that this engine manual may help
see page 17
ok this service manual should be the correct one
do you still need help?
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