in2pro

Some pinging is "normal" under heavy throttle, is my understanding of newer engines.
I have 71k on my 07 5.3l and use top tier (Shell, Tetco) regular 87 octane, also use Techron additive every 7-10 fill ups and I get some light ping or knocking if I get on it...

On a road trips with altitudes above 3k feet it seems to be more prevalent... so i go to a higher octane

Please do keep us updated on what you find

MDTAHOE

It should not ping at all. My 07 5.3 has 66,000 and does not make any noise. I have not noticed a ping on any of the ones I worked on either.

in2pro

My 97 would also knock a bit under a heavy load, using mid-grade was the fix for that... I'll have to pay a bit more attention to it now that its a topic and see if and when I notice it..
Seems that when its hot out is when I noticed it, and not so much since its been cool, but its getting up into the 90's so I'll have to start listening for it...

in2pro

"Knock is less common in cold climates" that can explain a lot...
when I do here it, it only momentary and I suspect that is because the knock sensors are doing their job...

Here is what Wikipedia has to say on knock / ping...

Engine knocking - Wikipedia, the free encyclopedia

magician

in2pro and MDtahoe - I've been reading up on knock sensors and Pre-ignition and how the tahoe ecu manages it. My question is, if I had a knock sensr that had failed or wasnt working correctly, wouldnt the tahoe have thrown a code indicating which one?? I mean it sounds like I may have some type of knock sensor issue but like MD said, it could be a lot of different things. I ran the tahoe lesterday with the ac on and got a fair amount pinging with moderate throttle and none that I could tell under hard accelleration? Could there possibly be some type of ecu update that may not have been done that addresses this?? Really perplexed now...

magician

Borescoping it this weekend didnt reveal any significant carbon deposits in any of the cylinders? Also, the pinging has somewhat decreased at this time though its still present in most of the places I've decribed earlier. Not real sure where to go from here other than take it to the dealership although, I'm sure since my tahoe has over 150k miles its going to cost me a good bit??

73shark

Sounds like a lean ping since it goes away under heavier load/acceleration.

tbb2

The original post asked but I do not see a response.

Does anyone have experience with using water injection to clean out a Chevy Express motor.

Would the year or size of engine matter?
I have a 2003 with a LQ4 6.0L V8, MFI.