My favorite fueling spot is right down the street and features alcohol-free gasoline. Maybe 40% of the time when I fuel up and head for the house, if I hit the throttle in an authoritative manner I get quite a detonation rattle. This only happens only on the first throttle-up after leaving the gas station.

When I refuel, I just let the nozzle shut off and don't squeeze a little more fuel in. This only seems to happen on the way home, so I would have gotten off the freeway a couple miles before I stopped for fuel. Also, my 03 XK8 never did this. I haven't pulled any codes because the car has never done this anywhere else, with or without refueling. Any ideas?

Mike

 

Are you refueling with the engine running?

 

Are you sure it's actually detonation? The only cases I've heard of turned out to be plugged cats.

 

+1 could be cat(s)

 

+1 also on the cats , i havn't heard any more pinging/detonation since i fitted new cat's .
but mine was more frequent than this ,a short pinging if i stabbed the gas at low rpm or a consistent pinging at WOT after about 4500rpm. at least get them tested as mine gave no codes ether.

 

I always shut down to refuel and this is the only time the car ever does it. The car has ~57k miles.

 

Try a different brand of gas.

 

Make sure that the Intercooler Pump is working. It runs all the time that the ignition is on and is located below the Air Cleaner.