I have a 2010 just cooper. When the gas tank gets about 1/2 empty I hear a thunk sound from the left rear about every 10 seconds when at a stop. At my last service I was told it was the gas tank changing preasure. Has anyone had this sound? Will it always hapen?

 

yes yes, I am suffering since last year....I don't know what's wrong...

 

Pretty sure I'm having the same issue.

 

I don’t think it’s as much of a problem as it is a little annoying... The consensus (here and other boards) is that it is the tank de-pressurizing. My ’08 does it intermittently, but it didn’t do it at all for the first 8 months I owned it.

 

When I turn my car off I notice that sound sometimes. I just figured it was the car trying to figure out pressures and such. However, I have never heard it while the car was on.

Personally I find the 'clunky' sound of the fuel injectors to be more bothersome.