06 E320 CDI Power Steering stiff at slow speeds - PeachParts Mercedes-Benz Forum

Ironforger · #1 03-01-2019, 10:53 AM

2006 E320 CDI, 297k miles.

Questions about the power steering. Something does not seem right.

I'll try to describe this: While driving at low speeds and getting ready to make a turn, let's say slowing down from 25mp to 15 - 10 mph and making a right hand turn onto a side street, when going int the turn the steering feels stiff as almost as if it's like a truck with manual steering. But, while sitting still parked at idle, the steering wheel turns real easy full left and right. It's fine while driving down the road at cruising speeds too.

So the ps fluid looks a lil muddy to me. I don't know if that has anything to do with it but Dealer records show ps fluid was changed / flushed once around 116k miles. I don't know if it's been changed since & can't rule out if someone put in the wrong fluid at some point etc.

The ps fluid level appears correct, and it doesn't really make any noise or winey sounds.

Regardless, first thing I'm going to change / flush the ps fluid to see if that helps.

Any other suggestions? What is the proper ps fluid for the 211 CDI? Is the Pentosin CHF 11 ok? Is there a ps flush remove procedure?

Thanks!

DieselPaul · #2 03-01-2019, 11:07 AM

They take CHF11S

Or buy it at the dealership, it's cheaper at the dealer than Pentosin is from some parts stores.

Mine feels stiff at low speeds too and I've changed my fluid.

shertex · #3 03-01-2019, 11:15 AM

Both of my CDI’s behave identically with respect to steering and neither is stiff at low speeds whatever the ambient temperature happens to be and whether or not the car is warmed up.

Ironforger · #4 03-01-2019, 11:42 AM

Quote:

Originally Posted by shertex

Both of my CDI’s behave identically with respect to steering and neither is stiff at low speeds whatever the ambient temperature happens to be and whether or not the car is warmed up.

Wish I could test drive your car for comparison! Like I said, our car seems fine in most scenarios, it's only stiff when making sharp turns at low speed. Turns fine no efffort when sitting still idle etc.

Does anyone know how many liters of CHF 11s Fluid I will need to change / flush the power steering system?

Thanks!

shertex · #5 03-01-2019, 11:53 AM

Quote:

Originally Posted by Ironforger

Wish I could test drive your car for comparison! Like I said, our car seems fine in most scenarios, it's only stiff when making sharp turns at low speed. Turns fine no efffort when sitting still idle etc.

Thanks!

And I wish I could drive yours....to see what effect the Rocketchip tune has had! I've been tempted but haven't pulled the trigger on either CDI.

BTW I used to live in Lawrenceville...and grew up in Skillman, just a stone's throw from you.

Ironforger · #6 03-01-2019, 12:43 PM

Quote:

Originally Posted by shertex

And I wish I could drive yours....to see what effect the Rocketchip tune has had! I've been tempted but haven't pulled the trigger on either CDI.

BTW I used to live in Lawrenceville...and grew up in Skillman, just a stone's throw from you.

I just saw Jeff (Rocketchip) to get the tune yesterday. I first met him 11 years ago when he did a tune for my VW Beetle TDI (which I still have but needs a cyl head job, blew head gasket at 325k).

As far as the Rocketchip tune for the 06 320 CDI, it's hard to describe. Just got this car last week. Bought it in limp mode.

Time line something like this:

Bought car last week. Drove home in limp mode: My reaction: Seems weak but handles great! Wont rev above 3k rpm and won't downshift.

Thurs eve I fixed the thermostat and got it out of limp mode . My reaction: DAMN!! way powerful. Awesome car!

Brought it to Rocketchip the next day. My reaction driving home:

HOLY $#*T!!! OMG!!! (is this too much power for my daughter???.) We'll see how she is with it after a few weeks. She's an experienced driver, has had several fast cars, Durango Hemi, Chrysler 300, 73 Buick riviera 455Ci (keeper, she still has the Buick

) But in all honestly may have to dial the Mercedes back. ).

Honestly I've never driven a car that handles better than my Beetle TDi until now. Amazing since the E320 is a heavy 5000lb car. It's for my daughter but I'm definitely going to get one for myself in the future.

Look me up if you ever get back Lawrenceville way! When did you move? What area of Lawrenceville where you in? I'm in the Historic Village area near the Lawrenceville school. I've lived here for 20 yrs and grew up in South Brunswick.

shertex · #7 03-01-2019, 01:01 PM

So sounds like the tune made a noticeable difference. When Jeff did the Stage 2 on my 98 I described it as noticeable but not dramatic....definitely worth it, though.

I lived just off L'ville Pennington Rd., not far from the school. This was for a brief period in the early 80s, just after high school.

Quote:

Originally Posted by Ironforger

I just saw Jeff (Rocketchip) to get the tune yesterday. I first met him 11 years ago when he did a tune for my VW Beetle TDI (which I still have but needs a cyl head job, blew head gasket at 325k).

As far as the Rocketchip tune for the 06 320 CDI, it's hard to describe. Just got this car last week. Bought it in limp mode.

Time line something like this:

Bought car last week. Drove home in limp mode: My reaction: Seems weak but handles great! Wont rev above 3k rpm and won't downshift.

Thurs eve I fixed the thermostat and got it out of limp mode . My reaction: DAMN!! way powerful. Awesome car!

Brought it to Rocketchip the next day. My reaction driving home:

HOLY $#*T!!! OMG!!! (is this too much power for my daughter???.) We'll see how she is with it after a few weeks. She's an experienced driver, has had several fast cars, Durango Hemi, Chrysler 300, 73 Buick riviera 455Ci (keeper, she still has the Buick

) But in all honestly may have to dial the Mercedes back. ).

Honestly I've never driven a car that handles better than my Beetle TDi until now. Amazing since the E320 is a heavy 5000lb car. It's for my daughter but I'm definitely going to get one for myself in the future.

Look me up if you ever get back Lawrenceville way! When did you move? What area of Lawrenceville where you in? I'm in the Historic Village area near the Lawrenceville school. I've lived here for 20 yrs and grew up in South Brunswick.

pawoSD · #8 03-01-2019, 09:15 PM

Stiff steering can be due to rusted/failing ball joints. My W201 had the same issue when I got it, upon inspection I found torn ball joint boots and rust inside. Replaced them and the steering was free and smooth again.