Engine Pings

I have a 1998 Mustang Gt 4.6L with 69,000 miles. For the last 2 weeks I noticed a pinging noise from the engine when I accelerate, around 2000 rpm.
I do not hear the noise when the engine is cold, only after the engine has run for about 20 minutes. Any suggestions?

I have a 1998 Mustang Gt 4.6L with 69,000 miles.
For the last 2 weeks I noticed a pinging noise from the engine when I accelerate, around 2000 rpm.
I do not hear the noise when the engine is cold, only after the engine has run for about 20 minutes.
Any suggestions?

Try cleaning the MAF sensor &
run some "Seafoam" through the engine to remove any carbon build-up.

If the temperature gauge is above normal range when the engine is warmed up replace the thermostat with a 180 degree. The temperature sensor for the computer may need to be replaced. If you have a resistor chip on the IAT (Intake Air Temperature) sensor take it off. The IAT could be faulty. As above, good advice. Do this before you take any more drastic measures. It could be the MAF is dirty and causing a too lean mixture. Carbon buildup in the cylinders could be causing the detonation. Does it "run on" after shutting it off. If so the Seafoam is good advice.

As said before, clean the MAF with an electrical parts or MAF cleaner that will not leave behind any residue. The Seafoam will help remove any carbon in the cylinders and is a good idea if never done before. And you may also want to check your O2 sensors with an OBD-II diagnostic tool if you have one available to you to ensure they are operating normally.

I took the MAF sensor out yesterday, sprayed it with some Maf cleaner,appeared to be very clean. Used Seafoam for the first time,pour some through the intake and some in the gas tank. Ater driving around today still notice the pinging. Not sure whether to try more Seafoam or not.

If the temperature gauge is above normal range when the engine is warmed up replace the thermostat with a 180 degree. The temperature sensor for the computer may need to be replaced. If you have a resistor chip on the IAT (Intake Air Temperature) sensor take it off. The IAT could be faulty. As above, good advice. Do this before you take any more drastic measures. It could be the MAF is dirty and causing a too lean mixture. Carbon buildup in the cylinders could be causing the detonation. Does it "run on" after shutting it off. If so the Seafoam is good advice.
So far I took the maf sensor out,sprayed it with maf cleaner,didn't appear to be dirty anyway. Ran Seafoam thru the engine and put some in the tank.
So far pinging is still there
My temperature gage stays in the normal range, never had any overheating problems.

You mention IAT sensor could be faulty, it that the sensor mounted next to the maf sensor?

Yes, it's next to the MAF.