2000 chevy blazer 4x4 2door 4.3L

so i found a leaking valve cover gasket the other day and replace the gasket and i wonder if the leak was causing oil to be pulled up into the fresh air tube???

i checked the pcv valve and it rattles and it kinda new anyway and it is also dry with no evidence of any oil at all, so i checked my gasket replace job for any air leaks anywhere by pulling out the fresh air tube out of the valve cover and plugged the hole and some serious vacuum was being pulled so i know the pcv is good and working and i have no gasket leaks.

so i checked a friend's 2002 blazer 4.3L and his fresh air tube is completely dry BUT his pcv has oil in it and the pcv tube...........WTF?????

if i had a blowby problem wouldn't it come out of the pcv first since it has high vacuum regardless of which side the blowby could be coming from and also since the fresh air inlet in the valve cover has a isolated box internally to stop oil from being splashed up the tube??

thanks!!

 

It sounds like your PCV valve is causing high vacuum in the crankcase. This can sometimes cause oil to pull back up and out the vent due to the pulsation in the crankcase pressure.

 

ok i'll get a new one, maybe the spring in it is weak, i'll clean out all the oil from the intake and the fresh air tube and report back what i find after a couple of days of running it at highway speeds to and from work,

thanks swartlk!!!

 

well i cleaned all the oil out of the main intake tube that sits right on top of the throttle body and cleaned out the fresh air inlet tube going to the crankcase and have been running it for a while now and guess what, NO MORE OIL, so i still replaced the pcv valve anyways since it was kinda cheap insurance, so the valvecover gasket leak was causing oil to be sucked up the fresh air inlet tube and right into the intake, again thanks swartlkk!!

 

Glad to help! Let us know how it goes long term!

 

Ok swartlkk its been over a year now and I still do NOT have any oil in my crank tube going to the intake or any at all in my intake tube or intake, everything is dry as a bone!!!! like I said it was the valve cover gasket that was not seated properly on the same side as the valve cover to intake tube, replaced the valve cover gasket and all is well!!!

 

Hey, i think i've got the same problem. I've got the banks sidewinder setup on my 6.2L and i keep getting oil in my intake. i would assume its from the fresh air inlet tube that goes to the crank case.

 

hey 82, i would check your turbo output side (compressor side) to see if the oil seals are gone out in the turbo, should have oil in the turbo to intake tube, also if your air filter is clogged will cause the turbo to suck oil through the turbo seals.