I recently bought another Impala (07 3.9L) since my last one treated me so well with no break downs or major issues. Well, this new one is some weird noises when the car reaches 40MPH and getting more deeper and louder as I accelerate.


When breaks are applied, the car doesn't make the noise. It sounds like when you rev your engine while parked but more deeper and not as loud. I first thought it might be the transmission but I checked the fluids and it shifts fine and the clutch is good. Oil was recently changed. My first thought was it could be bearings that might be bad.


Any advice on where I should be looking?

Does it change when steering left or right, then return when the steering wheel returns to center?

No, steering has no affect on the noise. Once I hit 40MPH and accelerate, this whiny noise begins. Getting worse on the highway. Imagine your car revving at the red line 5,000-7,000RPMS but your only in 2,000RPM. Noise stops once I get below 40MPH.

I'm completely out of ideas other than to ask if the car has any diagnostic codes set? It is a variable valve timing engine, so it does have me curious.

3.9L GM engine. Naturally aspirated. No fault codes and this started a week ago. Car doesn't overheat or anything. Which bearings usually cause these types of noises? I did notice some 'hissing' or 'deflating' noise coming from the engine when I open the hood.

The fact it changes with braking made me think wheel bearing, but steering doesn't change it (still could be, particularly in the rear). I'm out of ideas powertrain related.

If you hold the transmission in a lower gear, does the noise still appear at the same speed?

I will give that a try. I did shift it into 3rd and the problem still arose. I will shift it to 1st or 2nd and see if it makes the same noise.

Second gear should be sufficient. Just trying to isolate between the chassis (likely) and the RPM of the power train.

I'm back. Well, I shifted into all the gears (3,2,1) noise is still there. I'm thinking it'* bearing issue but not sure which ones! This is definitely coming from the engine though as it seems to sound like it'* revving in the redline when it'* actually in 2-3k RPMS. Once I release the accelerator, noise slowly stops until I reach 30-20MPH that it stops completely.