99 Noise/Steering Wheel Vibration Turning L or R

[dcgriswold]

My 99 Safari makes a buzzing, not a squeal, humming noise when I turn the wheel left or right while under power at any speed...such as in changing lanes. The turning movement, either right or left, does not have to be much. The sound is more noticeable turning to the right. You can also feel vibration in the steering wheel when making the turning motions.

The pump was replaced about a year ago...less than 25K. The noise just recently started. I believe the car has hydro boost.

Does this sound like the pump going out, or perhaps air entering the system through a hose or fitting? There are no leaks seen and the level is full.

The brakes work fine and the steering is smooth. The noise and vibration is annoying. Even if I turn up the stereo I can still feel the vibration.

Thanks for the help.

[Lumpy]

Does that only while rolling? Not while sitting still?

How about wheel alignment? Or do you feel like it's somewhere in the pump/gears?


Lump

[dcgriswold]

Hi Lump. I do not think alignment. The car goes straight down the road. I can take my hands off the wheel and the car does not veer. Also tire wear shows no signs of mis alignment.

The sound occurs when turning left or right...a buzzing that is also felt in the steering wheel.

It is more noticeable when rolling. There is a sound when stopped at idle, turning the wheel left or right, but that sound seems like normal ps sound. That sound is the same turning the wheel left or right when at idle. It is not a buzzing type noise I hear while rolling and the steering wheel does not vibrate.

[RECox286]

With out being right there to listen, it is difficult to say what the problem may be. Chevy describes several noises associated with steering pump problems,

Chirp, growl, groan, rattle, knock, swish, and whine. You have already mentioned that the system seems to be functioning as advertised, and the fluid level is OK.

There could be: excessive back pressure in the hoses, scored pressure plates, thrust plate or rotor, extreme wear of the cam ring, air in the oil, poor hose connection,

loose pump pulley nut, pump vanes sticking in rotor slots, pressure hose touching other parts of vehicle, and faulty flow control valve.

Perhaps you should take it back to the shop that did the replacement and see what they think.

Bob

[Dan411]

Remove your front rotors and look for any signs of metal shavings near the ABS censers.I'm having some what the same issues and I found that the inner sleeves inside the rotor will spin and cause,slop,play also,causing metal shavings.Check your inner & outer wheel bearings for slop after re-tightening and driving awhile.I tightened my wheel bearings and took it for a ride for about a mile and came back home.Jacked the Van up and found the wheel bearings had slop again after I just re-tighten them.I think GM made a big mistake with these rotors.These bearing sleeves are known to bust loose and spin like spinning a main bearing in a engine.I'm becoming a non-fan for GM anymore.Anymore GM's are junk!You would be better off buying a Jap car over a GM any day.

[RECox286]

It's a machine, and when the time is right, they will exhibit the honest truth, that the time for you

is wrong. Get used to the idea that you are dealing with heavy parts that move, sometimes faster

than they should, down the road, are subject to use and abuse, get to sit out in all sorts of weather,

and are driven hard and put away wet. I haven't seen one car (import or domestic) that hasn't been in

the repair bay for something or other. I think your distaste for GM products is somewhat jaundiced.

Of course this is my opinion and does not reflect the management's opinions in any way. Names have been

changed to protect the innocent, and no characters are in any way related to living persons, past or present.

Uncle Bob