Engine pinging over 45 mph

Texas Z · January 15, 2003

I have noticed in the past month that my engine makes a pinging noise over 45 mph. It only pings when the engine is warm (after about 10 miles of driving) and in overdrive over 45 mph. When I press the gas, not gun it, you can hear it ping but when I let off the gas it sounds normal. I drove in tow/haul mode and it didn't ping over 45. I only have 12000 miles on it and use Chevron 87 octane like the dealer told me too. I thought maybe bad gas but I tried different gas stations and several tanks later nothing has changed. I wanted to get some input before I take it to the dealer next week and they say its "NORMAL" like everything else.

Thanks

asepgrad98 · January 15, 2003

This condition may be the result of corrosion of the rear bank knock sensor due to water intrusion into the sensor cavity.

Have the dealer check TSB #02-06-04-023A :thumb:

woyster_00z71 · January 16, 2003

My truck was knocking alot awhile back. Not only in overdrive over 45 but pretty much everytime you got on the accelerator. I was using Sam's Club gas (about $.15 per gallon cheaper) but I switched to stricktly Chevron regular unleaded. I immediately noticed a reduction in the pinging and after a couple of tanks, the ping all but disappeared. Every once in a while it will ping but I attribute that to a bad tank of gas with some water in it possibly. Every 5000 miles just before an oil change I run a container of the Techron additive through it just for good measure. It has been about 6 months now, knock free. Chevron made a believer out of me.

B.J.

bigblackdog · January 17, 2003

I have the same problem. My truck didn't start "pinging" until about 20K. The dealer replaced both knock sensors and when that didn't fik it he "decarboned" the engine. When that didn't fix it he called GM who said, guess what? THAT IS A NORMAL NOISE! I also tried highest octane Sunoco offers, didn't do nothing. I did manage to get a 6 year 100K EXTENDED WARRANTY ON THE ENGINE. Problem is, if I ever want to sell the truck, anyone with half a brain is going to say what the #### is that noise??? I know I would!

bcfitzsimons · January 17, 2003

Hey guys-I usually post on the HD board-but my 8.1L has the same problem. I bought a cooler thermostat (160 degree) and the pinging was 95% better. The only time you'd hear it ping is when you stomped on the gas while in top gear on the highway. Then, I started using premium, and it went completely away.

Chevy also told me that it's a "normal engine noise." So I made them put their money where their mouth is and give me a 100,000 mile warranty.

Fitz

Texas Z · January 17, 2003

I have stayed with the regular 87 octane because I have been told numerous times that the trucks computer is programed from the factory for 87 octane and anything else is a waste of money.

bcfitzsimons,

I like your sig, "Now where in the #### is THAT noise coming from?" I feel the same way.

bigblackdog · January 17, 2003

I forgot to mention that my truck only "pings" under load. If it is in park or neutral I can rev it up with absolutely no noise whatsoever. When the dealer said this was piston slap which is "normal", I asked him why it only happens under load, he just shrugged his shoulders. These guys are getting brainwashed by GM and that is not good.

Texas Z · February 5, 2003

UPDATE: I finally got a chance to take the truck to the dealer and guess what they said, "ITS NORMAL". My service rep said they test drove it and heard the noise then hooked it to the computer and of course the computer said no problems so then looked for TSP and there were none. So that makes it "NORMAL". Do the techs know anything else but how to hook the computers to the vehicle and read codes? Do they have any mechanical training anymore?

How do I get GM to extend my factory warranty like a few of you did?

City_Slicker · February 5, 2003

Are you wanting the extended warranty just for the pinging?

If so, dont get it. If you reported a problem to the dealership before warranty ran out they still have to fix it. Its hard to tell you where to get an extended warranty not knowing what kind of dealership you bought it from.