Getting 10MPG, then 9MPG, now 8MPG in my 2008 M5 - The Unofficial BMW M5 Messageboard (m5board.com)

avlnch · 31st October 2009, 03:43

I brought my car to the BMW Dealer a few days ago because my car smelled like gas.. it reeked the garage up and slightly smelled inside of the car.

BMW replaced my charcoal canister because it was 'leaking'.
BMW also told me that my air/fuel ratio was off and they needed flashed my ECU (went from DINAN back to stock)

A few days went by, without the smell of gas, but I noticed I was getting 10MPG - Not normal.

One - two days later I was getting 9MPG, and now I am getting 8MPG - The garage and inside of the car also reeks of gas again.

Has anybody had this problem before? Any ideas? I will be bringing it back to BMW again but I'm searching for info on what the issue could be so I can give the dealer something to go on.

ManicM5 · 31st October 2009, 04:36

If you still smell gas in your garage, you are leaking gas, you aren't burning it in the engine. I had an issue on a previous car that was leaking gas at the fuel rail just above the injectors and another time a hose clamp was loose on a fuel hose, also just prior to the fuel rail. When you get home after a drive, open the hood. If the smell of gas hits you in the face, you have a leak in the engine compartment. If that's not it, you can try putting newspaper on the floor of the garage to see if you have a leak under the car somewhere.

However, whatever you do, be careful and have a fire extinguisher nearby. You have a dangerous situation if smell gas.

Come to think of it, bring it back to the dealer and let them figure it out. It's not worth the risk.

Good luck and check back when you figure it out.

bmwowns · 31st October 2009, 05:36

I have the same problem, in hope to resolve the issue I have brought my M into the dealer on 5 occasions (the most recent time, the dealer had my car for 11 days), however, the problem remains...

anucci · 1st November 2009, 01:31

Quote:

Originally Posted by bmwowns

I have the same problem, in hope to resolve the issue I have brought my M into the dealer on 5 occasions (the most recent time, the dealer had my car for 11 days), however, the problem remains...

11 days and they still did not solve the problem?
It is amazing how incompetent some of these BMW mechanics are. I mean, how hard can it be to find a fuel leak.
I would bring it to an indy that does warrantee work.

avlnch · 1st November 2009, 01:43

Quote:

Originally Posted by bmwowns

I have the same problem, in hope to resolve the issue I have brought my M into the dealer on 5 occasions (the most recent time, the dealer had my car for 11 days), however, the problem remains...

Please let me know what they say the problem is (when you get it back).