Thanks for the help guys, I haven't been on the past few days due to work, but I have a funny story to tell. Monday we checked compression on all the cylinders, all of them and found them to be 150-160 psi, which I suppose isn't too bad for an engine with 99k on it. Anyhow, I put some MMO in last week (drained out approximately 1 qt oil for 1 qt MMO). Monday night I took out the injector testor and tested the last 3 cylinders I didn't check the day before. Here comes to the story.

Apparently forgot to hook one of them up so CEL comes on, and I take a look to see my #6 injector unhooked, forgot to push it in until it clipped. Took out my code reader and sure enough, had a P0206 code and a P0306 code. Eh, "no big deal" I thought, so I erased the codes, and went to the store. Along the way hit the gas a couple times, wasn't sure if i could hear the noise, but assumed that because it was wet, my tires could possibly be losing traction a bit, and taking just enough load off the engine to keep it from pinging.

Long story short, went out today after it was dry, and hit the gas a handful of times. And just as mysteriously as it started, my pinging has vanished completely.

So..what made it go away? Could it be possible that it's taken this long for the pcm to 'relearn' how to idle with the 180* thermostat in? I've driven approximately 200 miles since I installed it.

Whatever the case, for now the sound has ceased ::knocks on wood::, and I have no idea what stopped it. Thank you very much to all who helped though, this problem became quite annoying, but yet seems to annoy me more somehow, maybe because I don't know how it was fixed.

 

The PCM 'learns' quite fast...10-30 minutes tops.

Weather has a lot to do with pinging.

Cold + wet + low barometric pressure weather = less pinging

Warmer + dryer + high barometric pressure weather = more pinging

 

Sounds similar to my case, only I believe mine is even worse.

Pings don't really become as noticible until after the truck warms up, say, maybe 5 miles down the road. The ambient temps here have been in the 30's this week.

I've been "dealing" with the pinging again now for over a year, but it is becoming worse and the power under acceleration is tending to drop off. Used to be, I only had the ping in high gear ( 5 spd ) , now it is coming on even while in 4th.

The truck has 125,000 miles on it. Before the 100,000 mile warranty ran out, thedealer changed the intake gasket twice. I had a local mech. change it again a couple weeks ago, told me there was oil, but the problem still persists. Also said his instruments showed nothing.

Esp. when under acceleration, up hills, it sounds like the engine will come apart any minute, so I back of the gas until it "almost" goes away.

This ping started back around 60,000 miles. The plugs, wires, and cap were changed as well as the first gasket. All was ok for a while, but came back quickly.

Please help.