Hi mate, did you need work done on the suspension at all? I got fed up of taking mine back to MB and haven't bothered since the warranty ran out. I'm getting instability too, but it feels like the left wheel sometimes has a mind of its own, and also goes through the left hand bends on the M6 with the wheel held straight. However, according to Mercedes, "they all drive like that". BTW I have a 220 CDI Coupe too.
Hi Chris.
I’ve just returned from having some warranty work done on the car over the last two days, and at the same time had it inspected for worn mounts, as per Ian Walker’s suggestion, and checks for other possible causes of poor ride .
When I took the car in, the foreman & I took the car for a drive. He commented that it was pretty good, not even drifting into the kerb, as many apparently do. We repeated the drive with a 1000mile like-for-like demonstrator. During those drives the road surfaces were pretty good and there wasn’t much to choose between the two cars. It was a good as gold when he took it over bumps which he said made any loose suspension components rattle.
Today the garage said they’d inspected it and found nothing wrong.
It was a stroke of luck that, while my car was in for the work I was able to keep the demonstrator – a C220 CDI coupe evo as a courtesy car. It had the pano roof and was even the same colour as mine (but had less toys
) (It’s AUX socket in the glove box worked well with the phone in its MP3 mode, so I’ll be fitting one. Oops, I digress).
I’ve not wasted the opportunity to assess the new vs old cars. I found the loan car to have a better ride. The snags I’d raised about my own car were almost all there, but far less pronounced.
A difference that may be significant; the demo loan car had Continental tyres at 33psi all round. Mine has Michelin Pilot Sport at 33psi rear and 30psi front. The Continentals gave a softer ride and there seemed to be less road noise, though, as the engine in mine seems a little louder, that could be due to some difference in the noise insulation.
The garage suggested reverting to Continentals come the next tyre change. They also suggested a geometry check, but that wouldn’t be covered by warranty so that would be £100 plus up to £90 for parts if re-alignment is required. Over the last two days I came to believe that the difference in tyres might be the problem, but driving back from the garage today I became less and less convinced. Going over a gently uneven road surface at 40 – 50 mph gives a feeling of barrel full of monkeys holding on to the roof and rocking the car from side to side. OK. I exaggerate, but you get my drift.
Fredfloggle has warned of the evo's intolerance to tyre pressure variations. I’m running as recommended, but I’ll give them a try at + and – 10% to see if there’s any noticeable difference.
Now that I know how the car should feel I’m determined to get to the bottom of this before the warranty expires.
As ever, if anyone has struggled to read this far, I’d welcome any further suggestions.
Cheers,
Rich
However I do wonder about gross suspension movements induced by the now ubiquitous SPEED BUMPS and their effect on suspension component longevity.
Of all the current models the SL would appear to best retain that over engineered approach of the old cars. In the troubled 90's and early 2000's the SL did much to keep that quality feel going albeit at a price when new, 
] I recommend either glow plugs or diesel injectors. Not too expensive to replace --unless they break when taking them out. Then its a cylinder head off job.
