2001 Pontiac Grand Prix 6 cyl Front Wheel Drive Automatic 150000 miles
I have a 2001 Grand Prix GTP Supercharged and since May 2009 I have had whining noise coming from the car. It is loudest inside the car. The history is: power steering line was replaced due to leak, system was flushed and refilled. Noise continued. Power steering pump has been replaced 4 different time with Delco parts, the rack and pinion has been replaced. The noise continues. The power steering was just flushed again today and GM power steeing fluid was put in (apparently the mechanic was using something else). The noise is still there when the steering wheel is turned left and right. Loudest when turning left. Any suggestions?
This dose sound like a faulty off loader vale with in the pump, am not sure how the incorrect oil would affect this, but I would have a word with a power steering specialist, under most conditions any squeal from the steering is generated with in the pump.
February, 1, 2010 AT 3:06 PM
The power steering consist of only 3 main components, the pump, the rack and the oil lines, as you have mentioned the pump has been replaced 4 times, and the rack has been also replaced and the noise continues, I mentioned that this type of noise in my opinion is pump related but like you point out same noise and 4 pump whats the chances. I feel that a rack will not in itself create this type of noise, but after thinking about this for a while, I am wondering if the pressure hose has partly de laminated internally and is creating a restriction which could cause this, I would be thinking that it would be the same both directions as we only have constant flow at this hose, my other concern is the wrong oil, has this done any damage to pump or rack seals and valves? Was the incorrect oil used with each change of pump & rack?
February, 2, 2010 AT 8:08 AM
Hi: The lines have not been changed to my knowledge and yes, the wrong oil was used with all pumps and the rack. I am going to guess that my next step would be to have the lines changed to see if that does the trick, if not, then there is a possibility of having to change the pump and rack and pinion again. Correct?
Thank you so much!
February, 2, 2010 AT 3:40 PM
I have been re reading all these posts and something just struck me. In your first post you mention that the lines were changed already, now what I feel we really need to do first up to get to the bottom of this problem is definitely prove that the power steering is actually the origin of the noise, I have be singularly minded that this is the case but now I am not sure, so what we need to do is drive the car with the power steering belt removed, now this will be heavy steering until you get some road speed up, so my suggestion is to get a fairly strong male driver to do this for you, you won't need to go far as if the steering is at fault, you will not hear any noise even just turning one corner, is this an option open to you to prove the steering one way or the other?
February, 3, 2010 AT 9:59 AM
Hi Mark: Yes, that is an option. I have a few friends that I can get to drive the car for me. I will let you know how this goes in a few days when I can catch up to them to have them try this.