A few weeks ago I replaced my valve cover gaskets. A few days ago I noticed oil smoke comming from under the hood. I pulled off the breather and smoke was rushing out of the hold. I have a PVC on the opposite side (to a vacuum source) there should be no pressure in there, just vacuum right?

My PVC still rattles when I shake it which sould make it still good. Does anyone have any ideas on what my problem is?

Thanks for your time,
Matt

 

i believe what you are describing is blow-by. this is caused by worn piston rings(tired motor). in a worse case scenario cracked rings.

 

It is a GM crate engine with less than 10k on it. I can't see worn rings as the cause. It has not done it the last few days and the engine was off when I pulled the breather.

 

my toyota 4 cyl. with 250000 miles on it blows out the breather....I believe it to be due to SHOT rings. still runs good though, burns little oil. how was it broken in?

 

Broken in good, normal oil changes. It only blows oil out of the breather when I remove it and the engine is off. I found a pinhole right above the #6 header primary that was causing the smoke when it was running or just off.

Also I never have had smoke come out of my tailpipes even at WOT.

 

What do you mean blows oil? I think you are just seeing steam or oil vapor! Nothing to worry about.

 

Yeah, that was worded bad. It blows smoke out of the breather after it is shut down. Thanks.

 

Yeah i would say that its just steam or oil vapor, nothing to worry about, my car does it too.

 

mine does it while running. i dunno if its blowby or not, but the motor has like 5K on it. should be, but it could be. shows 10% leak down too! sheesh.

 

It's normal for any engine to blow a little oil vapor through there. That's why we have pcv valves. As long as you're not losing oil it shouldn't be a problem.

Check your pcv for vacuum with the engine running.

 

I have no PCV. just 2 breathers. I had PCV on my exhaust, but it was sucking oil INTO the exhaust where it would leak out a small hole i have in my exhaust and cause the whole motor to smoke. sheesh.