my fuel tank will not take more than $20 worth of gas. that ends up being half a tank. my mb is a 2005 c320 sport coupe

 

how many miles per tank are you getting? is it significantly less than normal?
You could have a bad level sensor or something like the charcoal canister shutoff valve could be faulty. I would get someone to scan the car and see if there is a fault in one of the control modules that might help point you in the correct direction.

 

I'm getting around 200 miles per fill up.

 

yeah, that seems like too few of miles per tank to me unless its all city and traffic miles. If you have a fuel container (3-5 gallons), you could fill it and secure it in the trunk when you start getting low. At that point, just drive it until you actually run out of fuel to test if that fuel level gauge is actually accurate or completely wrong. Usually there is something wrong with a fuel level sensor inside the tank or in the Evap system (purge valve, charcoal canister or shutoff valve, etc).

 

Is it pretty expensive to repair? If not I can get it done but I paid 3600 for it and want to make sure it lasts for awhile.

 

That depends on what is actually failing on the vehicle. Find someone to scan the vehicle control modules and see if there are any faults to correctly diagnose any issues.

 

thanks I really appreciate it