I need some auto-level expertise!!!
 

I have a 1998 E320 Wagon with 52000 miles which I bought about 9 months ago.
1. The car has a nearly defeaning "roar" when going over small imperfections in the road; it handles big bumps and roads dips fine. It's most pronounced when decelerating!
2. It doesn't auto-level with a load in the back; it does make a "popping" sound as if it is trying to level the car.
Fluid is circulating in the auto-level system (no bubbles) but, I don't know the system pressure.

Two dealers say it just is a hard riding car but it's louder than my 1993 toyota corolla with 190,000 miles and worn shocks!! and it's much louder than my 1991 300E. So I don't think it's right. An independent mechanic thinks I MAY have a bad strut, but he's not sure.

If I can't find the problem I'd like to gut the auto-level system but I don't want to lower the car.

Two questions:

1. Anyone have a guess at the problem?????

2. Anyone know of a spring/shock set-up to put in the rear to keep the original height???

TIA

Intruder

I think there should be a way to change the auto level system so it will react quicker. I will have to think about this one.

Tyres?
 

If the suspension seems to be working, how about the tyres? Carcase construction and tread pattern can make a big difference.

Have you tried swapping the wheels from your 300E to see if this helps?

I've seriously entertained the tire theory since the tires are near the wear bars and am having those changed tomorrow. I'll see let you know what happens.

Intruder

Auto-level suspension
 

As far as I know, there is no way of changing the reaction on the auto-level struts. The only adjustmnet I have had performed in my previous W123 300TD and W124 300TE was in the kick-in weight sensor for the system to start working. I beleive the system remains off up to 250/300 pounds of added weight, after that the systems begins to work.

The dealer adjusted the auto-levelling device to start working only after 500/550 pounds were added, in this way I could board up to three rear seating passengers without having it to work at all times.

From many replies I have read in this site and from my own personal experience with wagons for 18 years they definitely tend to ride much harder than the equivalent sedans. They also have an inherent "boom" echo created by road noise. I understand the W210 wagon particuliarly rides much firmer than the sedan, unlike the W123 and W124 which came close to the sedan counterparts.

The tires are a very important issue. My E320T change its behavior completely (ride, handling, etc) after I changed from a set of BFGoodrich Touring tires to a set of High Performance Pirellis.


A. Rosich
S320, 2998
E320T, 1995

There are only four things that can go wrong with the autolevel system:

The pressure "bulbs" can go bad, leading to a locked rear suspension -- the struts cannot move because there is no gas space to compress -- the membrane bursts and the cylinders fill with hydraulic fluid. You will know if this happens because the tires are the only spring in the suspension and the rear end will beat you to death on bumps -- unmistakable bouncing. Not a bad fix, just a little messy. A rough driveway can just about shake your liver out!

The seals in the struts can go bad, in which case the car squats in the back and looks like the bumper is about to drag on the road. Not too hard to fix, but expensive, about $650 a side.

The actuating valve on the rear axle can go bad, causing the rear end to run up and down all the time, possibly in concert with road roughness -- or fail to actuate and refuse to level the car. The valve needs to be calibrated by someone who knows what they are doing to prevent excessive leveling and/or hunting.

And last, the pump can go, in which case the rear end usually sags, too. On diesels, the pump is on the engine, on gas models it is on the back of the power steering pump. It can be rebuilt separately. It is very expensive to replace.

I did the gas chambers on my 300TE -- the hardest part was getting the hydraulic lines back in -- they are short and stiff, so one has to get the correct end started first, and it took a couple tries.

Wagons in general are noiser that sedans -- all the rear end noise that usually gets muffled in the trunk space gets amplified by the rear floor instead. You might want to check to make sure the spare tire and tool kit are tied down properly, too -- if there is something loose, it can "dance" on the floor when you go over a rough spot, and make the car "roar". So can a bad exhause system, pounding on the floor.

Peter

Thanks for all the input. I was reviewing the schematic of the system and saw a DAMPER VALVE unit. Ant one know what this does???????????

Intruder

Don't know, but I suspect it is to prevent overly fast action on the system to prevent "bouncing" up and down. Strange things happen when the German manual get translated into English -- usually British English, at that. Damper = shock absorber = slows things down, absorbs vibration/ocsillation. There is, for example, a damper in the old sidedraft carb on the 115s filled with transmission fluid that prevents the mixture control needle from "buzzing" in the orifice (it was a variable venturi carb, pretty fancy in theory, a pain in the ass in practice).

I would assume that if it is bad, the autolevel won't work properly.

Peter

self-leveling system adjustment question
 

Is there an adjustment to the self-leveling system (on the E500)?

I need an extra 1/4 to 1/2 inch of height so I don't bottom out as I go up my steep driveway. Some posts suggest that there is a "lever" to adjust. Can this be done? Should it be performed at the dealer?

Your thoughts are appreciated. Thanks.

Bob:

Usually it is the length of the rod that goes from the sway bar to the control valve, but I'm not familiar with the E500, so check. If you do adjust, to slow, don't just screw it in or out a bunch all at once!

You should be able to get a little more height without too much trouble.

Peter

self leveling system
 

Peter (and anyone else who knows),

Where is the adjustment for the self leveling system?

Thanks,

Bob

Bob:

On the older models there is a lever on the sway bar that connects to the control valve with a link that has a threaded portion between to ball and socket ends. Should be in the middle of the say bar. This is the height control: unlock the nut at each end and turn the rod to make it longer or shorter to adjust the height of the rear suspension. Don't turn it too far, support the car while adjusting, and don't forget to tighten the lock nut down when you are done!

If you can't find the adjustment or don't want to damage anything, and independent shop or dealer should be able to adjust the height for you with no problem.

Peter