Hello all...
I've recently purchased a Grand Prix GT (2003 w/87000 mi.).
Since I have changed the oil (Royal Purple Synthetic 5w-30), I have noticed a knock coming from what appears to be the botton end of the motor, hard to tell exactly. The knock is not rythmic (it comes and goes only at idle). If I raised the RPM's the knock goes away.
The oil looks good (clean), but I'm not sure on the oil pressure, I assume its ok...
I have read that there is some piston slap with these motors, but this sounds like lower end. I'm wondering if the previous owner put something in the their last oil change to hide this.
Any suggestions?
Thanks much in advance...
