When I give full or near full throttle, I often get a pinging noise coming from the engine. Usually drops off after 3-5 seconds without any throttle position change. Most noticeable at highway speeds. Could be pre-ignition, and if it is, I am curious where best to start. I have tried using high octane fuel and Lucas Engine Treatment. Doesn't do much.

I also hear of a strange sound that comes from the intake and is often mistaken for pinging. I don't have any errors codes or check engine light on.

This is a very well maintained '99 v6. 180k. Original owner. No mods. Runs perfect.

 

Did this start up recently?

Might check the EGR system. The EGR exhaust passages can get plugged with carbon reducing the flow of exhaust gas to cool the engine.

Carbon can build up on the pistons raising the compression.

Have you tried different brands of gas?

How are the plugs, ign wires, etc?

 

Been doing it for a while. May be more frequent in warmer weather. Not consistent. Note: Engine will run strong at full throttle in top gears without a "ping" sound. This sound happens when adding throttle and bleeds off after the engine builds up torque and power.

Plugs and wire are about 40k old. This ping issue has always been a problem. Was my primary motivation for changing the plugs and wires. Didn't help.

I am intrigued with the fuel brand. I typically run Shell 87, however, the current tank is Vallero 87 which I reluctantly purchased out of necessity. Is there an advantage to using 91 octane fuel or do these engines like a particular brand?

Note 2: This vehicle spends a lot of time on the freeway. Minimal traffic with lots of extended 65-70 mph cruising; little stop and go. Most trips the engine runs for over an hour. Does this help or hinder carbon problems?

 

It appears the 1MZ-FE engine can suffer from pinging issues, something about the knock sensor locations and computer programming.

Not sure if one brand of gas is better then other. In some areas all fuel comes from the same refinery and the brand names add their additives. Fuel blends can change in warmer weather, sometimes alcohol is added.

Might try to find some kind of octane boaster and run it for a number of tanks.