Power Steering Cutting Out!
 

Hello out there,
The power steering on my 04',320CLK cuts out when slow movements like starting out or parallel parking. At those times its like driving a car with no power steering. Checked the fluid level and it is fine. No leaks from anywhere and no noise from the pump either. Car has only 68K miles.

How's the belt?

P/S Belt
 

Thanks for the response Skippy. The belt looks fine and the tension is good.

I wonder if this car has variable assist steering and the solenoid is sticking / engaging.

Look for a solenoid on the pump or steering gear.

If this car has a steering rack, the rotary valve seals may be worn allowing it to leak internally. This was a huge problem with domestic cars when steering racks became popular.

Steering
 

The car does have "speed sensitive steering" which is supposed to increase power assist in low speed tasks such as parking and reduces boost during normal speed for an increased "road feel"
It also has rack and pinion steering just added that year. It has such low miles to have the rack need rebuilding already 68K miles?

I wonder if a shop with Star (I think that's what it's called) would be able to get a code relating to something like that.

Star
 

Hi Skippy and thanks,
So have we come to that, where we at the forum with all the decades of experience here, are we held captive by codes? No disrespect, I speak in wonderment. I'm an old school ex-mechanic who has tried to evolve with the times, (mostly reading through this forum) but I guess now, even the symptoms that we used to rely on are out dated...not good or bad just a stark awakening!

I worked on old stuff rather a lot and I've had the opportunity to work on new stuff a bit. With the new stuff, the first thing you do is ask it where it hurts. Not everything talks to the computers, but I would think your speed sensitive steering might.

sensor
 

Seems to be the most logical thing is the sensor. Where it is, I cant find but it does seem to be the most logical thing at this low millage...thanks again

Sounds like the SPS valve to me

MB makes a repair kit #221 460 01 84

It's easy to test, though i would say usually these go bad and stay bad. resulting in little to no power assist all the time.

number 200 is the valve

Good luck!

Air in the power steering lines?