engine ping- need suggestions

Good deal on finding the issue! As an aside, if you have NEVER changed out your O2s, you should probably do it. O2s are good to around 100k miles (under normal circumstances). While the engine will still run, the O2s get sluggish and will cause the computer to compensate by throwing more gas at it, thus causing worse gas mileage. Just a thought.

UPDATE:

the pinging came back, not as bad as before, but it's there for sure. don't know what would cause this still.

basic rundown is this...
new plugs and wires last may (about 17500 miles ago)
new fuel filter at the same time
new intake gaskets and injector seals (uppers and lowers) in late march (barely 1000 miles ago)
new timing chain that i just finished today

still have the pinging under heavy load (towing) and at high rpm's

everything that i have done only seem to act like a bandaid, and now i'm at a loss. everything i've done needed to be done, but i really don't want to keep pouring money into it without some results pretty soon.

the only things that i can think to check next are
fuel pump
o2 sensors
MAF

anyone have any suggestions or good ideas of what to check/do next? with summer coming up quick, i'm about to need it to tow the boat to the lake, and i really want to have it nailed by then. thanks for the help.

NOTE: all this has been on 91 octane

Get a gauge on it and check the fuel pressure. Shouldn't be lower than 56 under any circumstance. Also have you tried getting gas from different brand stations? I recently found out all 91 isn't the same, and have a truck with a hurt motor to show for it.

well for starters, i've moved from amarillo to lubbock to go to school, and am constantly back and forth, so my gas comes from all kinds of places. i usually just hit whatever is close. not to mention that it has been doing this too long to suspect the gas IMO. but i do need to check the fuel pressure. i just can't help but think that if it was the fuel pump, i would have had a lot more serious issues by now.

i'll check the fuel pressure and report back.

what about the o2 sensors? this was my next big "suspect" to look into. i know i have not changed them in the 6 or so years i've had the truck, and i've put a little over 100k on it in that time.
i read a few article that list the o2 sensors as "maintenance items" that should be replaced every 100k miles.
i may do it anyway, but could they be to blame?

Hey do you have a programmer? I noticed my silverado started with a ping after I used the hypertech programmer..

Cheapest thing to eliminate from the vaiables, clean the maf with electronic cleaner. The maf can set a lean code and cause the engine to run lean and ping.
Second, regardless of if it's the issue, replace those o2's like the other reply said. There is a very good chance these o2's are causing the issue.

I'm assuming with all the things you've replaced, you'd know what an exhaust leak would be, but i'd have to be a big one to cause a lean code.

99% of the time, the lean code will be caused by:
a vacuum leak and the only way to diagnose for sure is with a smoke machine.
dirty maf
old or bad o2's
*on a relatively stock truck.

Quote:

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Originally Posted by farmtruc

Cheapest thing to eliminate from the vaiables, clean the maf with electronic cleaner. The maf can set a lean code and cause the engine to run lean and ping.
Second, regardless of if it's the issue, replace those o2's like the other reply said. There is a very good chance these o2's are causing the issue.

I'm assuming with all the things you've replaced, you'd know what an exhaust leak would be, but i'd have to be a big one to cause a lean code.

99% of the time, the lean code will be caused by:
a vacuum leak and the only way to diagnose for sure is with a smoke machine.
dirty maf
old or bad o2's
*on a relatively stock truck.

---

ok, thanks
i've smoked it since i replaced the injector seals and intake gasket and found no vacuum leak.

i'm gonna replace the o2 sensors as soon as money permits. i'm taking some summer classes this year, so might take a bit to get to it.
i'll check the fuel pressure just to be safe, i've replaced the pump on this truck 3 times since i've had it.
and i'll clean the MAF.

i'll report back ASAP and let ya'll know how it goes.

thanks again for the help.

UPDATE:

i cleaned the MAF and put it back together and initial results are good. no pinging so far. i'm a little stumped because i have cleaned the maf more than once in this quest to end the pinging. but i'm not complaining. the true test will be on a nice hot day with a trailer behind me.

thanks again for the help everyone, i'll keep ya'll posted

ok so the cleaned MAF worked for about a week, then it started acting up again. a little testing/tinkering later and i had a new MAF in it and its working great. go my 20mpg highway back and even towed the boat about 200 miles with no problems.

thanks again to everyone who helped me out, hopefully this time we got it nailed for good. :)