Hello all, I have a S60 120,000 miles and now when fuel tank is 1/2 - full tank of gas i get a thumping sound from the read under the back seats. Any idea what this is? I found somewhere else that its a fuel vapor canister.

 

Had this problem but it ended up being my cat was stuck in the trunk.

She lived.

 

clown

 

No, it was a cat.