i have a 2001 mustang gt that if the vehicle is cold no pinging noise what so ever,but when the motor gets hot or warm ,when u shift into first about 1500/ 2000rpm is when u hear the pinging and this goes on in every gear that u can hear until the motor noise is to loud to hear it it sounds like a little machine gun not real loud ping but loud enough to be aggrevating.u can also flutter the gas in between that rpm range when hot and u can make it do it but not constant because its not under a load please help with any info!!!!NONE of the local ford dealerships have a clue!!!!car only has 43,000 miles on it

check for exhaust leak, however i would think that would be more prominent when cold rather than warm. also what gas did you use last? this is pretty general im just stabbing at some basics here.

Good idea to check the fuel pressure and see what it is doing.

I have a 94 that was pinging exactly like yours. Only difference is mine is 5.0, but I bet it still uses same method to calculate load. I found vacuum leaks in a couple places in some 3/16" vacuum hose.

However the larger source of the pinging was a broken tube that connects the EGR Valve to the exhaust header on the right side of my engine. There was an expansion sleeve on that tube which had broke right in half and was creating two problems. A huge vacuum leak was one and an annoying exhaust leak for two. It was covered up with firesleeve so I didn't find the broken tube till I took the EGR valve off to service it.

The engine pings because it is getting more air than the computer knows about and only schedules enough fuel for the air it thinks it's getting based on MAF and IAT inputs.

So my 2 cents, check for a vacuum leak or two.