Questions and Answers

Pinging Ford F-150 Q. Good Afternoon Vince, I have a 1995 Ford F-150 4 wheel drive automatic transmission, 5.0 liter 302 engine with 144,653 miles. The truck is fuel injected and has A/C and ABS brakes. The trucks runs real well, but I'm getting a pinging noise when I press on the gas pedal from a complete stop.

The pinging noise only starts after the truck warms up. I changed the air cleaner (it was plenty dirty) but that didn't seem to help. Any help on this matter you could give me would be much appreciated.

Thanks,
Vince

A. You probably have a bad Knock Sensor (KS). The KS is attached to the cylinder block and senses engine knocking conditions. A knocking vibration from the cylinder block is applied as pressure to the piezoelectric element. This vibrational pressure is then converted into a voltage signal which is sent to the ECM.

When the KS detects the pinging, it sends the signal to the computer which retards the ignition timing until the pinging is gone. What you might try is running some Top Engine Cleaner (get it from a GM dealer) through the engine and see if that helps. You might also want to try a different brand or grade of fuel.