Powersteering rattling & groaning

franksm

Hi folks

'92 Merc 230CE with 100,000 miles on it: just recently, there's been a groaning/rattling from the front of the engine whenever the engine is idling and when the steering is being turned.

Guessing the PS pump is on the way out; its resevoir is topped up with fluid although the fluid doesn't look as clean as I have seen on other cars. Is there anything to do other than replace the pump ?

Cheers

Frank

Seth Brundle

The PS fluid shouldn't get contaminated in the same way that engine oil does so if yours looks weird then maybe get it checked out.
As for the noise, your description doesn't give us much to work on in terms of a diagnosis. It could be anything from alternator rattle to timing chain (if present) rattle to whatever.
My €0.02 - get thee to a dealer or specialist

franksm

Well, thanks, but going to a dealer is my last resort. I'm pretty good with DIY and never have good experiences with dealers, ever (Mazda and Vauxhall).

Did some more troubleshooting with the car:

1. with engine on turn the steering wheel to the left and to the right (not nice for the steering nor the tyres, I know). The goaning/creaking is still there.

2. stationary with engine off, moving steering wheel = creaks

3. coasting along at about 10mph, switch off engine; turn the steering left and right. With the engine off the steering still creaks

So I don't think it's the pump, therefore must be steering rack/box or track-rods, or other suspension parts.

Seth Brundle

The PS system generally groans when it is turned and the vehicle isn't moving. It is designed to operate with little road resistance (i.e. tyres moving) and also when power is supplied to the pump.
You do mention rattles etc which make me believe that it is worse than normal but until it is checked out you won't know for sure.

franksm

There's a "steering damper" mentioned in the Haynes manual, looks like a small shock absorber going from the steering rack to the chassis. I wonder if that is what's gone ?

http://www.kmsparts.com/views.asp?partno=05&ModelLevel=MB133&group=505

I'm going to raise the car onto axle stands at the weekend and have a gander - need to replace the antirollbar bushes too anyway

MercMad

The steering damper shouldn't really make any noise, its basically a gas/oil filled strut. Its cheap and easy to replace though !

I would also check the coupling at the base of the steering column and the rubber that surrounds this part. The rubber gets dry and makes strange noises and if the coupling is at fault it tends to get clunky ! You could spray lub the rubber to see if it helps !

If your car has the anti-roll bar with the tie rods with plastic ends then these can creak. Replacement is the only cure !

I think you need an extra pair oif hands to try to determine the exact cause !