P/S whine

[alvocado]

I’ve been having an ongoing issue with power steering whine despite bleeding the system multiple times. It seems to be getting progressively louder. The pump was replaced about 5 years ago with a GM unit.

I took a video of the pump with cap off the reservoir when bleeding today and am interested to hear if this is expected fluid movement when turning the wheel. There’s a lot of gurgling.

I don’t see any signs of a leak and the rack and all hoses were replaced in February this year.

Does this seem like a pump issue? One note: I don’t get any unusual bearing noise with a stethoscope.

 

[mikez71]

sounds bubbly.. or gurgly?
But since you're pushing the fluid in, that might be normal sound.. fluid going around the pump vanes with pump locked in place.

Perhaps an obstruction at the bottom of reservoir, at pump inlet? That might cause a whine?

 

[alvocado]

Good point on the gurgling noise coming from fluid passing over a stationary impeller. I was bleeding it solo and couldn’t look for air bubbles. I’ll see if the wife can lend an eye and watch while I turn the wheel.

 

[alvocado]

I pulled the belt to check for play in the pulley and there’s quite a bit of fore/aft movement but no lateral movement. Is any amount of fore/aft shaft movement within spec?

 

[rdezs]

Generally speaking, the the belt tension is completely managed by the belt tensioner. You'll see a line cast into the tensioner arm, with two lines on the tensioner body. It seems obvious correct tension is for the single line to be in between the two on the body of it. I would say if the tensioner has been on there for who knows how long, and that line is close to the maximum, might want to think about replacing it. Clearly a good time to replace the serpentine as well, and the idler pulley. Basic preventative maintenance at certain mileage.

 

[alvocado]

The belt is off for the P/S pulley check. Tensioner, idler, alternator and water pump are all new within the past 8 months.

 

[rdezs]

What brand tensioner?

 

[rdezs]

I'm not sure about any for aft movement as far as specs. But definitely you don't want any sideways movement in the shaft.

Technically the system is self bleeding. But even after having the front wheels in the air, and turning it locked to lock 50 times, I had visible air bubbles in the fluid for 2 days. On the third day there was no visible bubbles. If you still see bubbles in it, check your return line to the pump. Make sure you don't have any air getting sucked in.

 

[alvocado]

What brand tensioner?

Genuine GM. I swapped the tensioner and alternator trying to chase this whine and the P/S pump is the only remaining potential culprit unless I got a bad GM water pump. The water pump went in before summer and I don't hear any bearing noise with a stethoscope and there's no play with the pulley. The P/S pump doesn't exhibit anything out of the ordinary but I'm running out of options for a cause.

The whine definitely varies with RPM and is noticeable when revving with the car in neutral or park which ruled out the transmission. It's driving me nuts but worse, it has gotten louder and is a concern for long trips.

 

[alvocado]

One other note, I swapped the steering rack at the beginning of summer and replaced all of the P/S lines. I had no whine or noise for several months.

 

[rdezs]

I think I put my money on the pump then

 

[alvocado]

I'm going to pick up a pressure test kit and confirm there are no air leaks as a final check before swapping it. There's a chance of air being drawn in but no fluid leak.