Hey guys,

I recently purchased a 08 C300 from a 'mom and pop' dealer (Have only had it for about 1000 miles - 4 weeks or so). I bought the car while it was right about to go out of the manufactures warranty, so i took it to the Mercedes dealer, and had them run through everything. They found a few minor things, which were of course fixed under the warranty. I also purchased a 3 year extended warranty through a third party (Mostly power-train).

Anyways, last week i noticed that the check engine light came on, and after further investigation (checking the manual), it seems that i didn't tighten the gas cap enough. The check engine light cleared after the gas cap issue was resolved. A few days later, the check engine light came back on. I went to double check the gas cap again, and found that there was some ice buildup on the bottom of the metal fuel intake for the gas tank. I scrapped the ice off and re-tightened the gas cap, but i am still seeing the check engine light!

Is there something i could be possibly over looking? I am about to take it back to the dealer and see whats going on here!

Thanks,
Ben

 

you need to get the code causing the cel. this can be done a few ways. dealer, indy or buy yourself an obd2 scanner.

 

Could be many things causing it. As Blaze said the code or codes have to be read. I had a period of a little over a month where my 08 was in the shop every week because of the CEL. They replaced all four O2 sensors as well as the magnets on the cam shaft. I was not a happy camper, don't like using loners I want to drive my Merc.

 

Hmm, i came out to my car this morning, and now there is no check engine light.....

It looks like ill have to take it in to get the code once i see the check engine light come back on...

p.s. I changed nothing...

Thanks,
Ben

 

The code is still stored in the computer regardless of the indicator light. Go get it pulled.

 

I had similar issue. Took it to the dealer and it happened one of the exhaust sensors went bad. Dealer replaced it under warranty. Car has much more power now. So, take it to the delaer for check.

 

Did they say what causes such a problem? wonder how much it would have cost you had it been out of warranty.