75gasgas

2011 E550 approaching 100,000 miles and the end of my ELW. Here is my issue......as I slow down kinda fast and turn quickly(in either direction) I get a "groan" from what I'm guessing is the power steering pump?? Another time I get this is if I'm doing a quick U turn, where I'm braking quickly and pulling into a driveway. It is almost like the sensor for the speed sensitive steering can't keep up. Has anyone else experienced something like this? I'll definitely get it to the dealer before ELW expires just wondering if someone could help point me in a direction. Thanks in advance!!

PeterUbers

Mud

PS fluid breaks down over time and at that mileage it seems like a good idea to change it. I've had this issue before on other makes and except in one case (pump) the fluid change made a difference in both noise reduction and steering quality. Curious to see what the dealer says, good to be under ELW.

75gasgas

Thanks for the quick replies. I do not notice any change in the steering feel generally however, as I execute the the maneuver described above the steering does feel heavier and like the pump is not keeping up. With the holidays right around the corner I will have to wait a little to get it in. I will definitely post up what they find.

thefisch

Here is a thread on my recent PS sound issue in my 2011 E550 which 'sounds' similar to yours. https://mbworld.org/forums/e-class-w...ing-fluid.html

$9 fluid top up and it's been working fine in the 4 months since. Be sure to verify the fluid you have and need.

belarus27

low powersteering fluid.

Sunnyslope48

My OPINION is that the steering fluid should be completely exchanged with new fluid every 50K - 60K miles.

Easy enough to do yourself. Basic steps are:
After removing the fluid from the reservoir with turkey baster or suction tool, disconnect the return line and direct it to an empty bottle (add plastic tube extension). Fill the empty reservoir. Make SURE the reservoir is never completely empty during this procedure. Jack both front tires off the ground.

Key on; engine off.

Turn steering wheel lock to lock. Old fluid will be expelled via the return line. Top off the fluid. Repeat until the return fluid is nice and clean.May take 10-20 cycles to achieve this.
Replace return line and clamp. Fill the empty reservoir. Make sure to recheck fluid level after starting and getting fluid to operating temp.

300SE1993

Mine's doing this too. I was planning on changing out the fluid to see it it makes a difference. I'm pretty sure it's never even been looked at by prior owners.

75gasgas

UPDATE: Reading the suggestions here, went out and checked the fluid level. It was low. I first checked the manual it read that it was Dextron III. So, I stopped by the dealer and picked up a quart of their PS fluid. $12.00 and I was out the door. Got home and used my Mighty-vac to extract as much old fluid as I could and replaced it with new MB fluid. It seems to have worked!!! One thing I noticed about the marks on the dipstick is that they are very close together, and if I stopped quick I could easily imagine the fluid sloshing around enough to create a very low fluid situation where the pump would groan. I'll post up if the issue resurfaces. Thanks for all the help!!!