Started with a fuel smell. Diagnosed by my mechanic was the driver side sending unit, so I replaced with new unit, however the fuel gauge shows half tank when it is full and it would not move. Replaced the sender unit again because part was under warranty. Now the gauge shows OK, however it seams like it is adjusting itself while I am driving. I may need to take to mechanic again.

Most likely need to pay for the labor.. This problem should not happen in such a high class vehicle or any vehicle. Right now I am not sure how much fuel I have in the car since the fuel gauge is unstable. Very unhappy. Every part on this car cost a lot of money and repair is expensive, however it should not be for a major item like gas tank. I did not have this problem before the sender unit defect. Mercedes Benz should have a recall on this since other similar cars have had same problem.

I bought this MB CLK 350 Convertible about 6 years ago with almost 40k miles. I don't drive it much as it has only 45k miles on it today. I'm reporting a fuel sender leak as it is very much the same problem the NTSB investigated on the E series and the CLS Mercedes. I believe the platforms of the E and CLK are the same and share many of the same fuel delivery parts. Mercedes Benz has agreed to cover these same parts for 15 years on the E series and CLS but nothing else.

I seems to me that the NTSB closed their investigation prematurely and Mercedes Benz should extend the 15 year warranty to all Mercedes that share the same platform and defective parts. As I pursue a new fuel sending unit I am suspicious that there is an inherent design flaw that even the new unit will have leading to a recurrent problem. I think the NTSB should reopen the investigation and force Mercedes Benz to redesign the system and warranty the redesign.