2000 Grand Prix Load sound from front end

Have a 2000 3.8 Grand Prix with about 70,000 miles on it. Having a off and on probelm with it seems that when the car has been driven for a while and warm/hot and you go to a gas station or some sort or a short stop and you go back to start the car there is a somewhat load POP that comes from the engine area. It does not do it all the time, but it usally always seems to to it while it hot and once you start it back up fairly soon. Any one else had this problem any suggestions. Justin

It sounds like a slow responding EGR valve to me. It's staying slightly open when it should be closed, causing the pop.

how would the egr valve make such a noise? can you explain i guess i dont understand thanks!!!!!!!:banghead: