Engine or Tranny Ping

My 99 Z71 5.3 Chevy makes a pinging sound when in a strain. It sounds like the old pinging when the octane was low. My dealer can't do anything or doesn't know how to do anything without a code showing in the computer. I have read that the anti-knock sensor might be the problem as it sounds from behind the dash as next to the firewall somewhere. I thought it might be the tranny, but I just don't know. It just pings when in a strain like in a pull up hill or hard acceleration. The anti-knock sensor is located under the intake I think, so this would be a fairly major job to replace. Has anyone had any experience with this pinging? And had it replaced, etc...? Would the O2 sensors make the computer call for timing change? Is the computer doing its job? Could this be the problem? I'm just grasping for straws... Thanks in advance for the help...

Find a delaer that can read out the computer and see what is going on.

When going to the dealer ask for a factory trained tech not the grease monkey to work on your car.
If the dealer will not give you a factory trained tech ask for your money back and find a dealer that will.
Or go find a good repair shop.
Tips on finding a good repair shop.
Check around Ask around
Word of mouth.
Family friends coworkers neighbors business people and delivery people.
Mailmen and parcel delivery people get around and notice a lot of stuff.
Even a good parts house knows what shops are good and not good.
Chamber of commerce and better business bureau and city hall.
If you find a good referral to a repair shop go look them over and talk to them.
Look for a clean looking busy place with nice people running it.
Ask a few questions and ask about their qualifications and training.
Not all places have trained tech/mechanics.
If they do not find a place that does.
Even all dealers do not have all trained techs/mechanics.

I believe you may have a vacuum leak....check all vacuum lines and replace PCV.....also check the MAF for contamination and even clean with MAF cleaner by CRC ...and check all air intake rubber ducting... make sure you have good and the correct spark plugs...and wire resistances are normal...check fuel pressures just to ensure you have plenty of fuel pressure available...

If all this checks out it may mean that the KS is defective...your vehicle should never ping as the ecm/pcm/computer will retard timing considerably to prevent this...

then bring to a shop that will check for dtc and other defective componets like restricted exhaust O2 sensors etc...


hopefully it will be an inexpensive fix..


I almost forgot to say do not bring back to that dealer....they most likely want you to buy a new vehicle...to check the ks is very simple with a diagnostic computer hooked up....find a recommended repair shop that will help...get references first...

t

your timing is too advanced. you can't change this, as it's ECM controlled, and requires resetting ECM, and dealers won't do this. i have same situation with my ranger.

here's another suggestion:
try different gas stations and brands. what i have noticed on my ranger is that with better gas, it does not do this.

dissolve mothballs in gas and add to tankful. naphtaline, the active ingredient of mothballs, increases octane number of gas and reduces ping. maybe 2-3 balls per tank.

trannie is down and slightly to the right of your gas pedal, not behind the dashboard.

it may be out of time or the gas iff using 87 oct.put some higher octane in it or octane booster..maybe even sea foam thats what i use in my bike and my rv..