01 GrandPrix GTP S/C noise (not idle)

**rwilsonGTP** · 03-21-2011

Hello,

I am trying to diagnose a car problem. I'm not a car expert but all my recent headaches with my 01 GTP (150k miles) have been helping me learn.

Recently I started hearing a noise from the engine when accelerating and when making sharp turns (sometimes at idle, too). I can only describe the noise as the electrical sound an R/C car makes when it goes forward. Thus, I thought it might be the alternator. A friend suggested I might need a new serpentine belt.

I took the car in and the mechanic pointed to the supercharger : http://i4.photobucket.com/albums/y10...R/P5170050.jpg (picture grabbed from this post http://www.grandprixforums.net/super...ise-11972.html) and said that I need a new one.

I read the post I linked but the op said they were experiencing a rattling noise at idle, so I'm not sure I have the same problem.

Any help is greatly appreciated.

**blueguy** · 03-21-2011

If it is a rattling your hearing, that is the supercharger coupler.

ZZ Performance

Buy it there...and you never have to replace that one again. Just keep in mind your going to need to buy Anerobic sealer from your local auto parts store, not RTV...when you put it back together.

**BillBoost37** · 03-21-2011

For the same coupler at a usually better price Rolling Performance Home , he ships nearly the same day super quick and even has the rebuild instructions on his site.

At idle a rattling from the charger is typically the coupler. Most mechanics have little experience with a supercharger. If you are having some odd noises on sharp turns etc, I'd be thinking power steering rack or pump first. Having had RC cars...I'm all over the power steering pump whine. Keep in mind this is internet diagnosing from a general description. Can you get a vid of the noise? We love vids and can usually pinpoint the issue quick.

**rwilsonGTP** · 03-21-2011

I'll see what I can't do about getting a video...

Not a rattling noise, though. Although I did have a rattling noise about 6 months ago, but it was rattling while accelerating, not at idle and not while coasting. The rattling seems to have gone away, though.

**blueguy** · 03-21-2011

Knowing these cars a piston probably just fell out and found it way back into place.

Kidding though.

**FriboRage** · 03-21-2011

What does the noise sound like? I know RC cars can make a high pitched whine...

Im guessing you already know what the supercharger sounds like, but for the longest time, accelerating and going around sharp turns I was getting a high pitched whine (Im NA).

Turns out my power steering fluid was really low, and those sharp turns I think were running the ps pump dry just cause of how low I was.

I know a few other guys on here commented on having weird noises on acceleration and sharp turns, and fixed it with new ps fluid/pump as well.

Check out your ps fluid level!

**rwilsonGTP** · 03-21-2011

Ok that sounds good. I'll do that.

The PS is really weird, actually. Sometimes, every once in a while, the steering wheel is ultra-easy to turn, but most of the time the steering wheel is kinda hard to turn. It doesn't seem any harder today than it has the rest of the time I've owned it.

I asked my mechanic to check the PS for me but they don't communicate very well so I'll go somewhere else.

I sure hope it's the PS and not the supercharger! =D

**rwilsonGTP** · 03-27-2011

Problem solved. Added some PS fluid and no more noise.

First mechanic (as I said previously) said it was the supercharger. ($750 - $250 core + labor)
Second mechanic said it was the rack and pinion leaking oil ($650 after parts + labor).

All it needed was some PS fluid, which was free (had it laying around).