Hi, dilsingh. Assuming there is nothing else wrong (rack, low tire pressure, failing pump, binding parts like the tie rod end because she drove over a curb...) then changing the fluid may help. It's a regular maintenance item anyway. I added a bottle of the lubrisol to mine when I changed it, but that was more to try and shut it up. It does seem quieter since then. Either way the effort is normal to me.

Just buy the proper fluid at the dealer, it's not too expensive.

Take care and enjoy the ride,
Greg

 

The effort required to turn the steering wheel in my 2001 E320 is minimal, so there is definitely something wrong there. If it was due to the pump, I think you would hear some noise. If you don't know how long the fluid has been in there, it probably is time to change it but I don't think that would cause your symptom. Just guessing, but I think you should have your rack & pinion system evaluated.

 

That's kind of my take as well, MM, but it's lots cheaper to swap out the fluid than pay for a rack inspection. If it doesn't improve it, you're only out the cost of the fluid and a few minutes' time. And going back to the question of scrupulous mechanics, unless you already have a trusted indie, you roll into a shop and say "Hey, can you inspect the rack? My steering feels heavy" there are all too many cretins ready to take a quick look and come tell you "yep, we looked at it, you need a new rack" knowing that when they change it they'll swap the fluid, etc. and most of the time they'll be okay. If it turns out the pump was really the culprit they can say "well, we were concerned about that because that can kill the rack; we hoped it wouldn't and were trying to save you money, but that's life". And most people would probably fall for that nonsense.

To our OP, if you haven't changed the fluid, personally I'd start there. If you have already had that serviced, then go to your trusted mechanic and have the steering and suspension inspected and evaluated. Also, you didn't mention if this was worse when the car/climate was cold and improved when warm, if so that is a bit stronger pointer at the rack.

Take care and enjoy the ride,
Greg

 

my steering is quite heavy too, especially compared to the pre-facelift 320s I drove.

 

I have a w210 2001 E200k, what is involved in changing the fluid on these as my steering sometimes feels a bit heavy but after inspection I dont see anything obviously wrong.

Where do you drain off and then top up - also how do you bleed the system - is it just through constant turning of wheel with cap of the resevoir.

Cheers

MFK

 

Changing fluid is easy. It's just matter of pulling off the right hose and having somebody to keep turning the wheels while you feeding new p/s fluid and catching the old fluid. Just be careful not over fill it, because I over filled mine and I had to clean the floor of my garage in the morning.

 

I will change the fluid as recommended first. I guess I will have to use the syringe method and repeat the procedure 2-3 times. I do not feel any difference in the steering stiffness on cold days versus hot days. It is possible that there may be some sort of constriction in the fluid path, perhaps resulting from "sludge", however the fluid is very clear when sampled with the small dip-stick. Given the prices of 7 yr old E320s, I do not feel like spending a lot of money on this as I can manouvre the car OK, its just that the steering is a little stiff.

 

After you change out the fluid if it's still stiff you can put the front end up on jackstands and then start it and turn the wheel back and forth. That sometimes will help you find binding spots during the turning that can help a diagnosis. The fact that cold or hot is the same leans away from the rack, unless of course it was that way a year ago but the wife didn't let you know.

 

I owned an E320 2000 for a year and recently sold it and replaced it with an E430 2001 4matic. When I had them both at the same time for a couple of weeks (before I sold the e320) I noticed that the steering on the E430 is about 5 times softer. Before this I thought what I had was normal.
I just wanted to let you know my experience regarding your problem.
By the way the person who bought it did not say anything about the steering being hard when test drove the E320. (You can't really tell the difference unless you compare it with another car. This is how I found out about it)
Good luck.

 

you must have the strangest e430 4m out there.

you have no rough front suspension and soft steering. My steering is much heavier, and it rides pretty hard.

Maybe I got the amg performance e430 4matic option

 

Good advice as always Greg. I was probably thinking "rack" because I had one go bad on me, albeit a different car. And since you mentioned it, my steering was worse when cold, and it improved once the car warmed up.

 

I have no clue what your engine looks like, but if you posted a picture, I could help you out.

 

I managed to replace about half ( 500 ml) of the PS fluid, and ended up with a lof of air in the system. I managed to get rid of most of the air by turning the steering wheel side to side. I have not noticed any major difference in the stiffness between before and after but I will give it another few days beofre making any final judgements.Thanks to the help and suggestions from Greg and Musikmaan. It seems that on this model the only way to change the filter is to buy a new PS resevoir with the filter ( is there one in it ?) built in. I also seem to have the classic whine/chirp ( before and after PS fluid change) from the rubber boots at the ends of the rack-n-pinion, but since this is not reported as a functional issue, I will just live with it.

 

I hate to be the bringer of bad news, but it is definitely the steering rack. I replaced the pump and all that stuff and it didn't help at all. I had the same problem in my e320 4matic wagon and i just heard from my mechanic that the steering rack was a total mess. I will pick the car up tomorrow and hopefully see how it is. I am really not looking forward to the bill on that one.

 

I was afraid of that. The rack and Pinion itself is very expensive. Luckily the steering o my car is not so stiff as to be excessively(impossibaly?) hard to turn for me ( my wife has problems). Please let me know what kind of cost I need to be looking at.

 

If you are ok with a remanufactured steering rack, they are not too pricey. Install is not difficult for an experienced mechanic.

 

Oliver,

Who sells re-manufactured racks and are they avaiable from MB as recons?

 

(Steering Box and Steering Rack from Car Steering Wholesale), sales@CarSteering.com contact with Scott, they sell re-manufactured racks and give warranty.

 

Hi Benz50602,
If you got the Rack and Pinion replaced can you let me know what kind of cost we are talking about ? The mechanic I contacted wants $1200-1500.
I was thinking that since the steering is stiff in both directions, it has to be a common part that has the problem rather than the left or right side. This leads me to think (wishfully ?) that its perhaps the PS pump rather than the Rack and Pinion. However, I do not hear any abnormal noises from the pump, or leaks, and the PS fluid level is good.

 

Is there a way to check if the Power Steering Pump is functioning OK ?

 

I think they typically make an abnormal noise when they are failing (I went through that not long ago with my Toyota). Also, the steering seemed normal on the highway, but was pretty stiff at slow speeds. I hope you are correct because replacing the pump should cost a lot less than the rack and pinion. Hope this helps.

 

I looked at the rack mechanism from below and found that there was an electical connector ( 2 wires, I think ) that was just hanging there. I reconnected it, but I am not sure if the steering wheel is any easier to turn than before. Its definitely, much stiffer than on the S430. What is the function of this connecor ? Is it just a monitor of some condition or does it provide some sort of actuation signal ? If it provides a control signal then its strange that the steering worked at all, during the last 3 years that I have had the car ( bought it when it was about 4 years old).

The msytery continues ... luckily, I can still drive it wthout any problems.

 

Can anyone tell me the function of the electrical connector going to the rack and pinion assembly of an E320, year 2000, please ?

 

I still don't have my WIS laptop working and can't use this PC to check the EPC but at first blush I'd guess it is for the Steering Angle Sensor as part of the ESP algorithm. Why it would be unplugged is a mystery to me.

I'll look at the EPC tomorrow, perhaps in the meanwhile if someone else has the WIS or the FSM they can look at that too.

Take care and enjoy the ride,
Greg

 

It is speed sensor, make st wheel stiffer at high speed.

 

Thank you very much for the information. My problem is not at the high speed, but its strange that it had been unplugged, even though the socket for the connector is a tight fit. There are no noises from the power steering pump but perhaps it has become less efficient somehow.

 

What is the parameter steering option ? Seems like a strange option ? I ma amazed that you can have steering options !

 

The parameter steering option makes steering easier at low speeds and stiffer at high speeds.
It is a electrical actuated device inside the steering rack, narrowing or widening the flow of hydraulic fluid to the pistons.
It was an option in Germany, maybe series in the US-models.....

 

I checked my 2001 E320/E430/E55 sales literature and "Rack-and-pinion with speed-sensitive power assist and integral hydraulic damper." was standard equipment on all U.S.A. models.

 

I took the car into a MB certified mechanic (not the dealer) and was told that I need a new Power Steering pump. He did not do much diagnostics other than confirming that the steering is indeed stiff. His estimated job cost including the pumps is $575. Can this job be done DIY by buying a reconditioned PS pump, say from Ebay ? As I stated in previous emails, the PS does provide some assistance with the steering but not enough, and there is no leak. Is it possible that the PS resevoir may be clogged up, if it has a filter in it ? I did change some of the fluid a couple of months ago.

As always, expert advice from this site is greatlly appreciated.

 

The only advice I can offer is to not buy MB parts on eBay. Autohausaz.com or GermanStar.net would both be safer bets.

 

I replaced the power steering pump, but no improvement in the stifness of the steering. Its as stiff as before. I was surprised that it only took a small amount of PS fluid to come up to the right level on the PS dipstick. I did run the engine and bled the air in the system. Perhaps the PS fluid in not flowing throughout of the system. If I get a flush of the PS system, will that ensure that the fluid circulates around the systeme properly ?

Any other suggestions to try - the rack and pinion is very expensive !

This problem is a "nuisance" rather then one that prevents driving the vehicle.