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MB Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4317
Experience:  Mercedes Benz Qualified Diagnostic Technician
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2000 Mercedes SLK 230k with 43k miles when accelerating

Customer Question

2000 Mercedes SLK 230k with 43k miles
when accelerating hard (foot to the floor), the car stutters/lags around 4000 revs and doesn't speed up anymore. If I release the pedal slightly and then accelerate (not foot to the floor), it is ok. If I accelerate hard (but not foot to the floor), it is ok
What could this be? I have just had a full service on the car, so filters, oil, plugs etc have been changed
Submitted: 3 years ago.
Category: Mercedes
Expert:  MB Paul replied 3 years ago.

There are many different things that could be causing your problem & would always advise a fault code check on a diagnostic tool to see if any codes are stored.

The most common problem for lack of power on these engines is a faulty MAF (air mass) sensor. This is located in the air intake & is easy to replace.

Usually when the MAF fails it will store any or all of the following codes: The MAF itself, misfire codes, O2 sensor codes and/or fuel trim codes.

There are many cheaper alternatives to genuine but I would avoid most of these as many of the cheaper ones are poor quality in my experience. Stick with genuine or if buying non-genuine then ensure it is a Bosch product. This would be the same as from a dealer.

Best regards, Paul
Customer: replied 3 years ago.

I had read on the various forums that this could be the issue.


I mentioned the issue the garage that just serviced the car and he thought the MAF was ok and thought the first port of call would be to change the gearbox fluid/oil -could that cause the issue?

Expert:  MB Paul replied 3 years ago.

The gearbox oil would not cause the sympoms you have described - a bad MAF is the most likely cause but as said would recommend a diagnostic check first.

Best regards, Paul