Originally Posted by Scottish XF
Quick update:
The day I was taking the car to the dealer, the noise stopped!!! Can you belive that?! Hasn't happened since either - which I am graetful for, but I would have liked to know what was causing it in case it is something that is going to fail later on.
I'll draw a line under this for now, but let you know if anything else happens.
Again, thanks for all your input
Steve
As mentioned in an earlier post I made, (This may sound weird) but look at the gas tank. or do a search on this site for "gas tank implosion"... I think it was on this site or one of the MB SLK sites...
I vaguely recall an issue with the gas tank being sucked in by negative pressure because the vent was clogged or not attached properly. The sounf you are describing is exactly what I read...
The only way you can prove this to yourself is to run the car down to very low fuel level and then fill it. If the amount of gas it takes to fill your car is much less than the rated fuel capacity in the tank, you can assume the tank has been sucked-in and kinda crushed by negative pressure, much like sucking the air out of a plastic water bottle and then refilling it...
Worth a check, unless the dealer is willing to pull the under-cover of the tank and do a visual inspection.