Ping/Knock From Hard Acceleration

I was pulling out into some heavy traffic today and got on it pretty quick from a dead stop. Right as I pushed down the accelerator I got a pinging/knocking sound from the engine. I've never noticed this happening before. When I got home I tried to recreate it in the driveway and it did it again.

What gives?

2001, Auto, 58k miles. 87 octane.

 

Just to clarify, the sound goes away immediately. Even under heavy load the engine sounds normal once the truck starts to move.

 

Bump

 

I've started running 89 octane. On 87 mine pings below about 2300 rpm if I'm heavy on the throttle.

 

I had the same thing years ago. About a month after it started it threw a code and I changed out the MAF. Haven’t heard it ping since then.

Strange that it didn’t throw a code earlier. I don’t remember the code.

 

Was it pinging while driving or just as you accelerated? Mine doesn't ping at all under heavy load, like going up a steep hill for example. Just when I goose the throttle.

 

Detonation can be caused by many things. Most folks throw higher octane gas at it and hope it goes away.

First thing to do is to use higher octane gas and see if it goes away. This is actually a test, to prove the noise is detonation.

If it is, the next step is to figure out why (what's changed)

Rather than give you a list of options (I have to jet right now), a Google search using that term will give you things to start your diagnosis with.

BTW, you mention your driveway test. Detonation will almost never show on an unloaded engine.

 

When I hard accelerated. Didn’t matter if under load or not. Didn’t matter if I was starting from a stop or already moving. Once the needed hard accel was complete, no ping. I always use 87 octane.

 

I just goosed the throttle in my driveway with my foot on the brake.

 

Check the timing...

 

My '18 4Runner rattles, (pings) until warmed up, still hear little of it, the Tacoma, hardly hear it, 3400. Burn Shell 89 octane in both. This is 5th 4Runner, more then the others.
Crank

 

I just cleaned the MAF and the idle is smoother but I can still get it to knock when I accelerate hard from a stop. Guh.

 

Also, cleaning my MAF did nothing for my pinging

 

Things I would try

1) reduce carbon buildup on top of the piston and the valve which can raise the compression ratio. A few tanks of cleaner with PEA like gumout multi system or Techron.

2) Italian tuneup with cleaner above

3) check you knock sensor to make sure it’s retarding the timing slightly.

 

How do you do that check?

 

You know I've never had one go bad. I just know there is one. I'm guessing they would throw a code and could be seen by a OBD scanner or maybe measure the resistance (google it to find what it would be) using a multi-meter. I suppose the first thing I would check is to see if the connector didn't break off, dirty, or loose. Good luck.

 

Have you tried putting a higher octane gas in it to see if that gets rid of the pinging? If it does then it will help point you in the right direction