Air Pump Noise

[cjo]

Recently when starting my 2002 STS as soon as the engine is started there is a noise under the hood near the drivers seat of a motor turning. I've had it to the garage and was told this is an air pump and sometime its gets water in it and causes the noise. I was told all 2002's have this noise when starting the car for approx 30 seconds, and the reason I haven't heard it before is that perhaps the pump was not working. I am not mechanically inclined but feel this noise (something like a jet engine whine) should not be happening. Would appreciate any suggestions.

 

[caddiac]

My 2002 STS has never made a noise like you are describing so either the garage guy is wrong or my air pump is out as well. Ha! Imagine that something not right from the git go on a new car.

 

[momatmah]

Same problem on my '02 STS

From what you describe mine does the same thing, only not all the time. I have found that restarting the car will sometimes work, while sometimes it will stop on it's own, and other time not at all. There is no pattern to this so it is obviously not supposed to be. I thought it sounded like a actuato withing the air duct system that is trying to adjust per the climate control settings. However the air pump is something I will investigate.

I'll check back later if I find out any more. I am fairly mechanically inclined and will let you know if this is something that a DIY'er can handle.

 

[cjo]

I have been told by the Cadillac mechanics that this noise is the air pump, pumping additional air into the system upon start up during cool/cold weather. They stated that the breather pipe for this pump is near the lower frame and sometime water gets into the motor which causes the noise and eventually will riun the motor. In my case, the noise it noticed during cool/cold start-ups. Usually the first in the morning and then after setting for a period of time the motor whinning will last for approx 30 seconds. Perhaps its getting worse now that the cold weather is starting here in the North East and maybe after a very wet season, there is additional water in the motor. Either way, it's a new noise and would like to get it fixed and eliminated but am told that all 2002 STS's have the same noise.

 

[Jamler3]

There is an auto leveling system for the rear of the STS...
That compressor is mounted with rubber washers... Sometimes
in the cold they get compressed and the pump/compressor rumbles
a bit more than normal... It could be as simple as just tightening it down.