Can't fix Power steering noise
Thread Starter
Newbie
Joined: Aug 2013
Posts: 8
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C300 Luxury
Can't fix Power steering noise
The car makes no noise when cold and running.
Here's the sound:
http://www.videosprout.com/video?id=...7-f4fc08c1ce6a
After 2 or 3 miles, when car heats up, the sound begins.
It begins as only a warble-type sound when you begin turning, as you continue to turn the wheel it goes away.
But as the car comes to full operating temperature, the steering is always warbling, in all gears; PRNDL. The sound is most noticable in the cabin.
The power steering seems to function just fine.
The sound is louder when beginning to turn but continuing to turn makes it goes away, until you stop turning. when the warbling continues
Here's what I've done so far:
With car shut off, turning the wheel either way makes no noise (hot or cold).
Listened to each pulley (with a pipe), at rest and while turning, no warble there.
Listened to ball joints, connecting rods, at rest and while turning. no warble.
Sound was loudest, at least to me, listening (with a pipe) at base of the steering column, where it meets the rack. I put spray silicon all over this area including the steering u-joint, no difference.
I sprayed top of steering column, by the rubber boot up by the firewall; engine compartment side, no difference.
I moved the telescoping column fully in and out, no difference.
I tilted the wheel fully up and down, no difference.
I did a full flush (including the rack) of the power steering fluid with new spec. Mercedes fluid, no difference.
No bubbles in the power steering fluid before or after flush, although I did not vacuum pump the system.
No leaks in the power steering. The level was never low before changing the fluid.
The old power steering fluid's color was not bad looking, not cloudy, not dark, or bits of anything in it.
Maybe a dry bushing/bearing somewhere in the steering column, bad pressure relief valve in pump, Steering control modue?
I did clean the engine with Gunk, and spray it down with water, maybe? (not sure) before this noise was noticable, not sure if there is a correlation there, but it's sure possible degreaser/water got in somewhere it shouldn't.
Help? Thanks!
Here's the sound:
http://www.videosprout.com/video?id=...7-f4fc08c1ce6a
After 2 or 3 miles, when car heats up, the sound begins.
It begins as only a warble-type sound when you begin turning, as you continue to turn the wheel it goes away.
But as the car comes to full operating temperature, the steering is always warbling, in all gears; PRNDL. The sound is most noticable in the cabin.
The power steering seems to function just fine.
The sound is louder when beginning to turn but continuing to turn makes it goes away, until you stop turning. when the warbling continues
Here's what I've done so far:
With car shut off, turning the wheel either way makes no noise (hot or cold).
Listened to each pulley (with a pipe), at rest and while turning, no warble there.
Listened to ball joints, connecting rods, at rest and while turning. no warble.
Sound was loudest, at least to me, listening (with a pipe) at base of the steering column, where it meets the rack. I put spray silicon all over this area including the steering u-joint, no difference.
I sprayed top of steering column, by the rubber boot up by the firewall; engine compartment side, no difference.
I moved the telescoping column fully in and out, no difference.
I tilted the wheel fully up and down, no difference.
I did a full flush (including the rack) of the power steering fluid with new spec. Mercedes fluid, no difference.
No bubbles in the power steering fluid before or after flush, although I did not vacuum pump the system.
No leaks in the power steering. The level was never low before changing the fluid.
The old power steering fluid's color was not bad looking, not cloudy, not dark, or bits of anything in it.
Maybe a dry bushing/bearing somewhere in the steering column, bad pressure relief valve in pump, Steering control modue?
I did clean the engine with Gunk, and spray it down with water, maybe? (not sure) before this noise was noticable, not sure if there is a correlation there, but it's sure possible degreaser/water got in somewhere it shouldn't.
Help? Thanks!
Last edited by rob4; Aug 22, 2016 at 12:25 PM.
Super Member
Joined: Aug 2013
Posts: 709
Likes: 48
From: NFLD
2017 C43 AMG, 2010 C350 4Matic, 9 Motorcycles
If you have a mechanics stethoscope, try putting it on the power steering pump.. If its not the rack it sounds like (with all the things you've already tried) the issue could lie therein.
Thread Starter
Newbie
Joined: Aug 2013
Posts: 8
Likes: 0
C300 Luxury
Listening through the PVC pipe, resting on the PS pump and by the PS pulley made no warble, but down by the steering column/rack union I could hear it pretty well, but not sure why I'd hear is loudest there, at the rack. If it is a constant sound, I'd think it would be in the pump. I hear it pretty clearly in the cabin, not nearly as good outside the car, as it's competing with the motor noise, but I still hear it.
Question: Do racks EVER make noise when parked? Nothing moves in the rack when the car's parked right? Just fluid going thru the low pressure bypass, going thru the rack, and back to the reservoir? When I flushed it, fluid flowed out of the rack to the return line freely, when cutting the wheel stop-to-stop, both ways. No problems there.
Also: Does a steering column EVER make noise when parked? Man, I'm totally humbled by this one.
Happens parked and driving. Yet when under pressure, sound increases with initial cut of wheel, then is silent until pressure from turn is relieved.
Saw this, Can I rule this out?
https://mbworld.org/forums/c-class-w...ing-noise.html
Question: Do racks EVER make noise when parked? Nothing moves in the rack when the car's parked right? Just fluid going thru the low pressure bypass, going thru the rack, and back to the reservoir? When I flushed it, fluid flowed out of the rack to the return line freely, when cutting the wheel stop-to-stop, both ways. No problems there.
Also: Does a steering column EVER make noise when parked? Man, I'm totally humbled by this one.
Happens parked and driving. Yet when under pressure, sound increases with initial cut of wheel, then is silent until pressure from turn is relieved.
Saw this, Can I rule this out?
https://mbworld.org/forums/c-class-w...ing-noise.html
Last edited by rob4; Aug 22, 2016 at 01:07 AM.
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Joined: Mar 2008
Posts: 3,714
Likes: 56
From: 1 hours drive north of Sydney Australia
2007 W204 220CDI Classic Sedan
Yes, Rob, I think you are on to something here. What does the module look like? Let us know how you go. JC
From Sportstick :-
"Yes, as Glyn helped out with my last post on this, the steering wheel module produces a high pitched, almost electronic-sounding noise, mostly just off center in either direction. The noise seems to come from the steering column, just forward-in-car of the steering wheel hub. Not a DIY to me! Repair is about $700, but dealer goodwilled it, including replacing the module in the column. "
__________________
From Sportstick :-
"Yes, as Glyn helped out with my last post on this, the steering wheel module produces a high pitched, almost electronic-sounding noise, mostly just off center in either direction. The noise seems to come from the steering column, just forward-in-car of the steering wheel hub. Not a DIY to me! Repair is about $700, but dealer goodwilled it, including replacing the module in the column. "
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Thread Starter
Newbie
Joined: Aug 2013
Posts: 8
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C300 Luxury
Here's what it sounds like (might have to copy/paste it in your browser)
http://www.videosprout.com/video?id=...7-f4fc08c1ce6a
http://www.videosprout.com/video?id=...7-f4fc08c1ce6a
Last edited by rob4; Aug 22, 2016 at 12:22 PM.
