Thread: Need help..gm/pontiac tech's cant figure this out.

Well, I’m pretty sure I know what it is. By pretty sure I mean like 95%. The noise is your power steering pump, I’ll try to explain.

I’ll give my opinion in retaliation to your observations.

#1 That is the pressure relief opening and shutting in the pump. Not many cars are designed to steer a car that isn’t moving. To be brutally honest that is driving school day one stuff, stop doing that to your car. It isn’t good for any steering pump to do that.

#2 That is the pump cavitating from being speed up.

#3 The pump noises will vary depending on the temperature of the power steering fluid. As the fluid heats up the noise generally reduces to the point of being silent.

Power steering noises are pretty common in GPs. I noticed my pump makes more noise on my 07, than on my 02 GP. The truth is that GM power steering pumps are way over built and hence tend to be noisy at times. My car is noisy at cooler temperatures when I accelerate and turn at the same time. But after a taking about 3-4 turns in the morning it will be basically run totally silent. The good news is none of these noises means the pump is failing or even being damaged, it is just how they are. If you drive your car at reasonable acceleration rates and make about 4 turns (couple right and a couple left) then after a few miles of driving they tend to run silent. Now if your pump always makes noise, then IMHO you have a problem. Good luck.

I'm thinking if they replaced the power steering pump then the problem is not a relief valve opening. The valve is designed to only open if hard over. This is not what he's describing. I'm not certain what kind of rotary vane pump GM uses these days but I'd guess it's likely a spring offset cam so it does not have to use the relief valve at higher engine speeds.