Pinging when engine hot - any way to eliminate?

JeffP · June 26, 2002

1995 Tahoe 5.7L TBI 60,000 miles.

I have been burning 87 octane gas in this ride since day 1. I ususally stick with the same brand ( Exxon or Mobil ).

I have developed a "ping" I think after the engine is warmed up or after 20 mins or so of driving. It doesn't do it 1st thing, only after the engine has been driven for a while.

Anyway it's a light pinging on takeoff in the 1st & 2nd gear at low RPM. It's not terribly loud, but I can hear it with the windows down. I guess it's not so much a "ping" as it is a "gurgling" sound. I guess it's a "cheap gas" sound, but like I said, I've always put 87 in it, so don't know why I have a problem.

Had a full tune up in the last month: plugs, wires, cap, rotor, air filter, pcv valve, fuel filter. I also just had my cat. converter replaced and my O2 sensor. The gurgling/pinging noise was there before & after all these components were replaced.

Any ideas how to get rid of this? I tried an octane boost additive ( Outlaw ) but no dice. Any other additives which might make this go away?

p.s. I have no power/performance issues, this sound is just annoying me as it makes my big V8 sound like it's a piece of crap when I'm pulling up the street. It only acts up after it's been driving a while.

Thanks in advance,

JP

June 27, 2002

I would play with the base timing ever so slightly.

An advance or retard as little as one degree could make a lot of difference. Mine is set at 3 degrees advance. Not by choice, I couldn't get a wrench on it and it runs great, so why change?

A few guys here have told me they get a smoother ride with up to 5 degrees advance.