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
