C215 Hard suspension

[alexanderfoti]

Hi all

I have posed this question on the other side, but would be interesting to hear or anybodys opinions.

I recently lowered my 215 55 amg. It made the ride harsh so I put it back to standard height but the ride is still harsh.

Its especially bad on the rear with potholes etc causing the rear of the car to become unsettled (yes I need to do my subframe bushes too).

I have recently replaced the front accumulator (pulsation damper) and have carried out a leveling under STAR.

Something odd is that it does seem random. On a long drive it can go from being hard to OK on the front and back and vice versa.

There are no codes or anything on those lines. STAR says:

under Symptoms - Vehicle damping too hard:
Switch (Comfort and sport switch is in "sport" position)
The acceleration sensor values are implausible but are not yet displayed as a fault

Under the second one, it says to test the sensors by moving the vehicle sharply and seing if the value changes by >50 mv

 

[m2287]

Hi all

I have posed this question on the other side, but would be interesting to hear or anybodys opinions.

I recently lowered my 215 55 amg. It made the ride harsh so I put it back to standard height but the ride is still harsh.

Its especially bad on the rear with potholes etc causing the rear of the car to become unsettled (yes I need to do my subframe bushes too).

I have recently replaced the front accumulator (pulsation damper) and have carried out a leveling under STAR.

Something odd is that it does seem random. On a long drive it can go from being hard to OK on the front and back and vice versa.

There are no codes or anything on those lines. STAR says:

under Symptoms - Vehicle damping too hard:
Switch (Comfort and sport switch is in "sport" position)
The acceleration sensor values are implausible but are not yet displayed as a fault

Under the second one, it says to test the sensors by moving the vehicle sharply and seing if the value changes by >50 mv

I had similar after lowering mine, it was the bump stops on the rear struts, only cure is new struts. You can see the bump stops if you cut the plastic cover off on the strut, it will be obvious if it's knackerd, its a kind of yellowy colour!

 

[alexanderfoti]

Even when put back to normal ride height?

 

[m2287]

Even when put back to normal ride height?

If you lower it too much, the shock will hit the internal bump stops which basically smashes them and causes a jolty suspension. It is the part labelled "t" in the design diagram on this page:

ABC Suspension Strut

Don't get me wrong, I might be wrong but it's pretty much exactly what happened to me!

 

[alexanderfoti]

Ah, I see what you mean. It is certainly a possiblity, although I only lowered it approx 20mm at the rear so I would be suprised.

Also it being on/off makes me think like its an electrical fault?

 

[m2287]

Does it feel like the car slips to the left or right when you hit a bump?

 

[alexanderfoti]

Yes, but I put that down to the subframe bushes.

 

[m2287]

Have you checked the camber arm bushes? They are another thing that perish easily once lowered

 

[m2287]

My thinking is that if your bushes are all dead then your level sensors could be going a bit crazy and giving wrong readings to the ABC ECU, that could lead to all sorts of problems...

 

[alexanderfoti]

Its probably a good idea to get under the car completely and have a good look at the back of the suspension I think.

Its funny you mention that. The last time I leveled it, the car thought it was higher on the rear right by 10mm, although I checked with a tape measure and they were all level.

 

[WG M-B]

Its probably a good idea to get under the car completely and have a good look at the back of the suspension I think.

Its funny you mention that. The last time I leveled it, the car thought it was higher on the rear right by 10mm, although I checked with a tape measure and they were all level.

Was this before or after the lowering flash???

 

[alexanderfoti]

It was lowered with Links but I didn't check the values before I lowered it.

The values are off with the links at stock ride height.

 

[alexanderfoti]

Right rear is off the left rear by 10mm or so

 

[m2287]

Right rear is off the left rear by 10mm or so

I would check all your bushes then replace if necessary, get a proper 4 wheel alignment and then see if the problem is still there.

 

[alexanderfoti]

Had a play today.

Put the links back to stock height (approximately). All level sensors show inside the specified voltage range (2.00-3.00v) apart from rear right which shows 1.80v. I am going to replace this one on saturday, I can only assume that the sensor has failed whilst being moved.

 

[alexanderfoti]

Rear left level sensor replaced today.

Much better now! The old sensor was rock hard and very very stiff to move. I can only assume it was bending the rod slightly and not reacting quick enough. Happy now!

 

[alexanderfoti]

An update on this one, shortly after replacing the car started doing its old tricks again.

I have now replaced the front and rear suspension acumulators and the return accumulator:

Went for a long test drive on all different types of roads.

It does seem better, I would say 30/40% better. I think the old spheres where worn. On the plus side it does seem as though my rear valve block has been replaced with the newer/updated one at some point (so replaced in/around/after 2007/08?).

I think the remaining issues with ride quality are down to my choice of wheel. 19inch AMG Style IV are a fair bit heavier than than the style III that they replaced. Unsuprung weight has the worst effect on ride and handling I belive.

All in I feel happier that they have been replaced and may now turn my attention to the suspension/bushes.

 

[DSB SL AMG]

After you have finished replacing the suspension bits as already mentioned I would definitely get a 4-wheel alignment check to ensure suspension geometry has not been affected...to adjust you will need the bolts from MB.

An update on this one, shortly after replacing the car started doing its old tricks again.

I have now replaced the front and rear suspension acumulators and the return accumulator:

Went for a long test drive on all different types of roads.

It does seem better, I would say 30/40% better. I think the old spheres where worn. On the plus side it does seem as though my rear valve block has been replaced with the newer/updated one at some point (so replaced in/around/after 2007/08?).

I think the remaining issues with ride quality are down to my choice of wheel. 19inch AMG Style IV are a fair bit heavier than than the style III that they replaced. Unsuprung weight has the worst effect on ride and handling I belive.

All in I feel happier that they have been replaced and may now turn my attention to the suspension/bushes.

 

[alexanderfoti]

Good idea, I will check the bushes etc first then will pop by wheels in motion. I need to see them for something next week anyway so will get the details then. Thanks