Hi all. Was wondering if anyone could help with a diagnosis.
I have found a few threads on the forum that deal with similar issues and got some spot on advice about issues I was having with my previous
C Class. (Air con controller, main dealer fix...ouch)
I didn't notice the problem on a test drive, but then I was taking it very easy down country lanes.
When I drove the car home from the dealer, I noticed the following:
under hard acceleration or kick down the turbo seemed to go into limp/protection mode. Most noticable from standing start under acceleration, as soon as turbo cuts in, it limps. If you use the throttle progressively and don't kick down in lower gears, the car is fine and absolutely flies at motorway speeds. The car doesn't smoke at all under acceleration and is otherwise driving perfectly.
I have also noticed that at idle in park there is a barely detectible vibration in the cabin but it is definately there, almost a slightly lumpy tickover, but more subtle. The car idels at 700rpm and temperature is pretty much always 90C
When I called the dealer (non Merc) he said the previous owner had "boosted " the turbo (does he mean remap?) and limp mode was engaging to stop the turbo getting over boosted and damaged.
I am not sure I accept this as it is spoiling an otherwise fantastic drive. If you took you car to get it chipped or mapped & it came back like this, surely you would take it back for the original map?
Other threads suggest a duff MAF and I would be happy to change it myself to save a two hour trip to the dealer
Aside from this issue, I am really enjoying the car and it seems to be doing 35mpg combined.
Anybody had these problems before? Any advice on best way to diagnose. The computer is showing no errors and the car has been serviced by specialist a few months ago.
Thanks for any suggestions
Mark
I have found a few threads on the forum that deal with similar issues and got some spot on advice about issues I was having with my previous
C Class. (Air con controller, main dealer fix...ouch)
I didn't notice the problem on a test drive, but then I was taking it very easy down country lanes.
When I drove the car home from the dealer, I noticed the following:
under hard acceleration or kick down the turbo seemed to go into limp/protection mode. Most noticable from standing start under acceleration, as soon as turbo cuts in, it limps. If you use the throttle progressively and don't kick down in lower gears, the car is fine and absolutely flies at motorway speeds. The car doesn't smoke at all under acceleration and is otherwise driving perfectly.
I have also noticed that at idle in park there is a barely detectible vibration in the cabin but it is definately there, almost a slightly lumpy tickover, but more subtle. The car idels at 700rpm and temperature is pretty much always 90C
When I called the dealer (non Merc) he said the previous owner had "boosted " the turbo (does he mean remap?) and limp mode was engaging to stop the turbo getting over boosted and damaged.
I am not sure I accept this as it is spoiling an otherwise fantastic drive. If you took you car to get it chipped or mapped & it came back like this, surely you would take it back for the original map?
Other threads suggest a duff MAF and I would be happy to change it myself to save a two hour trip to the dealer
Aside from this issue, I am really enjoying the car and it seems to be doing 35mpg combined.
Anybody had these problems before? Any advice on best way to diagnose. The computer is showing no errors and the car has been serviced by specialist a few months ago.
Thanks for any suggestions
Mark
