DIMBS

INITIALLY WAS HEAVY WHEN TURNING LEFT. WAS TOLD TO BUY NEW STEERING PUMP. I CHANGED PUMP; PROBLEM PERSISTED. WAS TOLD RACK. IT WAS SOFT JUST FOR A DAY. THE FOLLOWING DAY, IT WAS HARD TURNING RIGHT. WAS TOLD RACK WAS FAULTY, FIXED ANOTHER ONE BUT STILL NO CHANGE. IVE CHANGED RACKS 3 TIMES, NO EFFECT. I HAVE NOW PARKED THE CAR.

homeofstone

Did you change the power steering hoses? Hoses can wear on the inside and then cause blockage. I would have started there unless the rack was leaking or pump was making a noise.

cmriv

Is this a OEM MB rack? Did you replace oil tank for p/s fluid as well? Filter inside
tank can get clogged with debris and cause fluid restriction issues. Is there any air in the system?

cmriv

and what the fella above me said. Lines may be collapsed too

gafitanu

Check the speed controlled proportional valve in the steering gear.

cmriv

not all models obtained this feature. but its worth a look. I think if that valve is faulty it's going to throw a esp light.

gafitanu

The reason I pointed to the valve is because mine exhibits similar behavior when is cold outside for the first couple of turns after starting. It doesn't throw any codes and I can overpower it. It's quite expensive that's why I didn't change it.

cmriv

the part itself is pricey?

arto_wa

New "Genuine Mercedes-Benz" Power Steering Proportioning Valve $405 at online vendor!



Proportioning Valve



You are not alone with W211 power steering issues - here are couple of links to what others have written:

https://mbworld.org/forums/e-class-w...-rack-bad.html

https://mbworld.org/forums/e-class-w...e320-w211.html



Not all W211 have the speed sensitive power steering.

cmriv

that is pricey sheesh. Well hopefully OP figured it out. I don't know if i've personally seen one of those valves bad. I've seen them leak but haven't drive a MERK with SPS with a bad valve. It would be nice if we knew whether or not he has code 213 (SPS)