Thread: BAD Negative Crankcase Ventilation after Upper Intake Plenum Replaced

Hi everyone,

I recently had the upper intake plenum replaced on my 2003 Pontiac Grand Prix GT (3800 non-supercharged). The following day it started making an intermittent squeal noise. I have been driving it this way for about a month and a half now.


I thought it may be crankcase ventilation so at lunch time today I ran it until it squealed..just a few seconds after it started and then removed the oil fill cap. This took a ton of effort to do and it has more power than a new vacuum cleaner.

I have already replaced the belt and tensioner pulley. The tensioner pulley was quite loose but the new one is nice snug bearing, spins freely, not the cause.


Is it possible the upper intake plenum was installed incorrectly or is plugged somehow, or could this possibly be caused by the PCV valve? It started right after I got it back from the shop so..


Thanks

Originally Posted by Fivefingerdeathpunch

I would first replace the PCV as its a under 10 dollar part, then if it continues take it back to the shop.

Will do...this has been my DD for 4.5 years, great car. I have it up for sale but no bites yet, probably asking too much

I'm thinking since I've done so much work to it I may just keep it for the winter. I pick up an '06 Dark Cherry GXP with only 60,000km tomorrow

Will let you know how the PCV valve swap turns out.

Thx

Originally Posted by rpenlington

Will do...this has been my DD for 4.5 years, great car. I have it up for sale but no bites yet, probably asking too much

I'm thinking since I've done so much work to it I may just keep it for the winter. I pick up an '06 Dark Cherry GXP with only 60,000km tomorrow

Will let you know how the PCV valve swap turns out.

Thx

Yup...no o ring on the pcv valve. Off to the dealer I go. Surprised a ring would cause that much of an issue with neg. pressure

Hey guys...none of the canadian stores seem to have the o ring lol...nothing like overpriced dealer rubber. Will let you know how that works.