2004 GTP CG, weird engine noise

Greetings all,

I have a 2004 GTP CG with about 22,000 miles on it. The engine has started making a strange noise, usually after starting from cold. When I give it gas, there is a loud whining sound that is quite noticeable and more than a bit disconcerting. Any thoughts?

Thanks!

sounds like a possible upper intake leak. Once the engine heats up a bit, everything expands and te noise quiets down or goes away completely.

Did the noise become evident when the weather got colder?

My air intake system is noticably noisier when the weather is cold. You can hear the supercharger much more clearly until the engine warms up. If this is what you're experiencing, it's normal.

Is your car running ok?

sounds like a possible upper intake leak. Once the engine heats up a bit, everything expands and te noise quiets down or goes away completely.
Really? I have the same thing going on. I've been thinking bad pulleys, PS pump or possiblly tranny. But I did just install a FWI about 2 weeks ago so it makes sense. I just never would have thought a leaking intake would make a whine like the one I'm hearing. I'll check it out. Actually I think I'm gonna put the stock air box back. I lost 2MPG after installing a 9" K&N cone.
Even though its not my original post, thanks for the tip richtazz.

Yes, the noise first manifested itself one evening a couple months back. It wasn't real cold out, but it was certainly a cool late summer night in Canada. It does seem to improve, but not necessarily go away, when the car is fully warmed up. I haven't noticed any performance issues.

Have you and how often do you check and change you superchargers oil?

I have not :( Probably wouldn't be a bad idea. Is that not something that the dealership would check during a maintenance visit?

They wont check it. In fact I was a the dealer a few months ago for a tranny check and told them to change the SC oil and the guy said "GM says dont change it at all". So I went to the parts desk and got 2 bottles of SC oil and did it myself.

Really.. What's the recommended replacement cycle on the oil?

The owners manual recommends topping it off every 30,000. I talked to a GM parts guy and he recommended that I replace it all. The only way to drain it is siphon it out. I did so and the oil was brown. It took over 2 bottles to fill it. The new oil is clear. I felt good changing it. Price per bottle at dealer 7.08 including tax.

Talked to dealer two weeks ago the change mine. They said $50.00. I said I'll do it myself.
Try this; http://www.clubgp.com/cgi-asp/mods.asp?modid=13
If you have a pump from a water bed, it's faster.
http://img.photobucket.com/albums/v425/kustomkid54/1998PontiacGrandPrixGTP003.jpg

CAUTION......used supercharger oil smells like dead goat ass!!!!

Also, don't be alarmed when you pump out the old oil........it will not be full. I have helped change oil in several and have never seen one filled completely from the factory.

HAHAHAHAHAHaHEHEHEHEHEHe You are so right!!!!!!!!

Interestingly, this morning the car didn't make the whining noise when I first hit the road. I warmed the car up for say 90 seconds - 2 min or so, and left. Temperature outside was -2c or about 28f. Whining didn't start until the car was well warm. It's real noticeable going through a McDonalds drivethrough :) Giving it a tiny bit of gas, the whining is the most noticeable. Methinks I should take it to the dealer, but I'm sure I'll get one of those "It's not making the noise right now" situations happening.

It never hurts to get it checked out.......especially when it's under warranty. :grinyes: