View Full Version : Mystery Engine Noise

03-01-2001, 01:54 PM
After installing a new (power) steering gear box in my G20 6.2 diesel van, I have noticed a high pitched moaning type of noise that only happens at the upper RPM range. I bled the power steering pump (I THINK I did it right) and filled the tank to the mark. Any ideas what could be causing this?


03-01-2001, 05:01 PM
It could still be air in the fluid.If the fluid is white and foamy,this may be the problem.A short drive,and then letting the vehicle sit overnight and it should go away.If not,look at the belt tension,and the power steering lines.If the lines are bound up,or grounding against the engine,frame or box,it will make that type of noise.

03-02-2001, 09:10 AM
Thanks for the tips! I've looked at the fluid and it doesn't seem to be foamy or have bubbles in it but I'll look more closely. How would the lines touching the block, or each other, or grounding to the chassis affect it?

03-02-2001, 09:58 AM
The PS lines make noise,it's just insulated by the line.If the line is pulled tight or touching something,or holddowns are missing,the noise will be amplified.Usually makes a moaning noise.

03-02-2001, 10:14 AM
Thanks again! You guys and this forum are awesome!

03-02-2001, 04:08 PM
I bet it's probably the line hitting something, but something you should have done when you filled it, is jack up the front end, and turn the tires back and forth, adding fluid as you went. This makes sure you get all the air out. I did it when I put the last pump in, and wow, it worked so much better. Just a thought.

03-09-2001, 03:10 PM
Thanks for the advice. I already did the wheels off the ground thing and the wheels on the ground thing. I saw a post on the diesel page about noisy alternator belts on diesels. Seems like cheapy aftermarket belts will make a moaning noise at certain RPM's. Sure enough, the alt belt is waaay down in the alt pulley groove and kinda buckles up on the outside edges. Purchased the Goodwrench version and hope to have it installed tomorrow. I'm also going to isolate / insulate the ps lines while I'm at it.