slight engine thumping, ideas?
So when the A/C is off, no music and the engine is hot there is a slight thumbing sound coming from the back of the engine it can only be heard when is at a standstill. Now I think that I'm getting paranoid it's not loud however its having me worried as I used to have an Audi A8 which made similar noise and it was a (drive chain slack)$$$$$!
Any ideas to what it may be or is it just normal engine sound ?



