Help! Strange Noise

[C4_Lover]

Hello, I have a 1996 CE LT4 coupe with 29k on the speedo. When I accelerate (even at slow speeds) I am hearing a hi pitched wistle that appears to be coming from the right rear of the car. When I let off the gas the noise stops but as soon as I apply the gas the wistle noise comes right back. I am certain it is not wind noise. Any help would be appreciated.

Thank you.

 

[air1jpg]

It could be wheel bearings or your rear gear going out.

 

[tonylong]

It could also be vacuum related. Does it come/go with engine speed or vehicle speed? Try it with the tran in neutral at the same range of engine speeds - if the noise persists with the car stopped, it's not in the drivetrain.

 

[C4_Lover]

It could also be vacuum related. Does it come/go with engine speed or vehicle speed? Try it with the tran in neutral at the same range of engine speeds - if the noise persists with the car stopped, it's not in the drivetrain.

It only comes and goes when I accelerate.(slow or fast). I had the car in neutral and it does not make the noise.

 

[tonylong]

It only comes and goes when I accelerate.(slow or fast). I had the car in neutral and it does not make the noise.

Aha! When in neutral does it whine when you increase engine rpm's to the same as when running in gear?

 

[Hib Halverson]

Well...the right rear is where the evap canister is. The way the noise is described in the first post sounds very much like a vacuum leak of some kind and the leak might be related to the canister, its connections or the hoses leading to it.

Has the check engine light been on at all?

With the engine idling in neutral/park do you hear the whistle when you rev the motor?

 

[C4_Lover]

Aha! When in neutral does it whine when you increase engine rpm's to the same as when running in gear?

No, it dosen't whine when in neutral and rpm's are the same when running in gear.

 

[C4_Lover]

Well...the right rear is where the evap canister is. The way the noise is described in the first post sounds very much like a vacuum leak of some kind and the leak might be related to the canister, its connections or the hoses leading to it.

Has the check engine light been on at all?

With the engine idling in neutral/park do you hear the whistle when you rev the motor?

No check engine light, and no whistle when in nuetral or park and revving motor.

 

[tonylong]

No, it dosen't whine when in neutral and rpm's are the same when running in gear.

Well, in neutral the drivetrain is out pf the equation so it's likely in the engine. Vacuum hoses are my first thought however the "whistle" might also be a "whine" such as bearings. Engine noises should happen even when at rest. Can you make it happen when parked? Also, I think there is a vacuum line to an auto-tran for down-shifting. If you punch the throttle while cruising does it happen as it downshifts?

 

[C4_Lover]

Well, in neutral the drivetrain is out pf the equation so it's likely in the engine. Vacuum hoses are my first thought however the "whistle" might also be a "whine" such as bearings. Engine noises should happen even when at rest. Can you make it happen when parked? Also, I think there is a vacuum line to an auto-tran for down-shifting. If you punch the throttle while cruising does it happen as it downshifts?

I can't make it happen when parked. When I punch the gas the whistle noise dissapears, but comes right back after I lift and then accelerate.

 

[C4_Lover]

Thanks for the info everyone. I'll let you know how it turns out. I'm leaning toward a vacuum leak myself.

 

[sweabe]

Have you tried to apply the brakes while standing still, gear in drive and press the accelerator, the engine together with the exhaust will then twist, it could be a crack in the exhaust. :confused

 

[C4_Lover]

Have you tried to apply the brakes while standing still, gear in drive and press the accelerator, the engine together with the exhaust will then twist, it could be a crack in the exhaust. :confused

I'll try that. Thank you