Supercharger question on 2000 GTP

[Pacer]

Hello,

I picked up a 2000 GTP recently with only 9000 miles. It had been sitting in a collection for 2-3 years without being started. I had it transported to a local dealer where they changed out all the fluids, etc.

The car runs great, however I am wondering what this noise is on acceleration. It sounds like a rattlesnake hiss or the perverbial "card in the bicycle spoke." And it's on all acceleration, easy and hard. At the same time, I do NOT hear any whine whatsoever from the supercharger?? I've never owned a GTP before (had a '99 GT) but I've always heard about the whine from the supercharger, and I'm concerned that I'm not hearing it on mine.

My question is...is this hissing noise (or sometimes sounds like pinging noise) related to the fact that I do not hear the supercharger whine? I'm thinking there might be some kind of leak somewhere.

Any advice is greatly appreciated!

P.S. The boost gauge is showing plenty of boost, if that helps any.

 

[Fivefingerdeathpunch]

9000 miles??? or 90,000 miles??? just wondering.

As for the noise, made you have vac leak or that could be the supercharger couple going bad.

as for the whine, you will prolly only hear that if you are modded, that stock air box helps prevent that "whine".

 

[Pacer]

9000 miles??? or 90,000 miles??? just wondering.

As for the noise, made you have vac leak or that could be the supercharger couple going bad.

as for the whine, you will prolly only hear that if you are modded, that stock air box helps prevent that "whine".

Not a typo -- 9000 miles, well 9100 as of tonight. It's a former pace car that was used by NASCAR at the track in Richmond, VA in 2000/2001.

The local dealer said the sound was a normal 'supercharger sound', but I think I'll seek a second opinion somewhere else. I'd post a picture of it but I can't get anything to upload for whatever reason.

 

[Fivefingerdeathpunch]

use photobucket and put the picture on here

 

[Pacer]

 

[blueguy]

A few things...

1) The DIC boost gauge isn't very accurate...unless you like telling your buddy's your boosting at 8 lego's not 6. Get a cheap-o boost gauge and tap it into the vacuum line behind the blower under the MAP sensor..."T" it in. That way it'll tell you your real boost levels AND if you have a vacuum leak or not. It should sit about -20 vac at idle...and probably make about 5-7psi at WOT right before you shift.

2) Check for vacuum leaks...if it has sat for a long time it most likely has suffered from the typical 3800 dry rotted vacuum lines...there are 2 sets...one from the Throttle Body to the EVAP solinoid on the top of the back of the blower...2nd one is the full set from the BBV (Boost Bypass Valve), to the FPR (Fuel Pressure Regulator), to the LIM under the blower snout (Lower Intake Manifold), around the back to the bottom of the MAP sensor where your "T"-ing in the boost gauge too.

3) A good way to check for leaks is when the engine is warm and idling...spray some brake clean around the area where the hiss is coming from...it will suck in the brake clean and change your idle...and possible make the car want to die...then you know you've found your leak.

Hope this helps.

 

[Ryansgtp]

Care to add how much you paid for the car?

 

[Reptile]

Well, for starters, if it's got the stock airbox, you won't hear the supercharger whine. The duct work has nooks and crannys to keep it from being noisy period. As far as the sound...it could be pre-detonation....not even KR, What you should probably do for starters, is maybe change the plugs and wires. I've had a couple of cases where I've heard this noise, and that's exactly what it was. Not saying that's the case here, but it should probably be a start.

 

[Pacer]

Thanks Reptile. A local dealer said it was a "normal supercharger noise." Needless to say I'll be seeking a second opinion.

Ryansgtp -- let's just say it was...enough...:th_nervous: lol.