Pinging on 87

[STORMIN08]

1. Where are you from ??? i would certainly think your fule source is not the bad, to be causing this

2. show these to the dealer or contact GM service program and discuss

3. see if the dealer after reviewing these logs, will do a new knock sensor, it could be a faulty unit.

i would think, if it is that apparent, that you would possibly see a FLASHING check engine light when this happens...i have on 2 different occasions during long road trips, usually right after a recent fill up some where

 

[smokey_mountain]

1. Where are you from ??? i would certainly think your fule source is not the bad, to be causing this

2. show these to the dealer or contact GM service program and discuss

3. see if the dealer after reviewing these logs, will do a new knock sensor, it could be a faulty unit.

i would think, if it is that apparent, that you would possibly see a FLASHING check engine light when this happens...i have on 2 different occasions during long road trips, usually right after a recent fill up some where

1. I am in NC in RTP, it is quite developed and all other Tahoe owners I speak with do not seem to have issues with pinging.
2. I did show to two dealers, they said "so what, we see nothing, we hear nothing". GM dealers in NC is the reason, I probably will stay away from GM going forward, I was interested in a diesel Tahoe but given the "do not care" from the GM dealers, I will not be considering GM anymore.
3. I just filled up with 87 Shell to see how bad 87 is, and it pings crazy loud. I did it in case the dealer has the hearing problem.
4. That is what the dealer told me "no code -> no repairs. Nothing wrong with your truck. Logs are nothing."

 

[smokey_mountain]

Hey, @randeez can you please let me know if the Spark Advance data on this plot is looking normal?

 

[randeez]

its not really that easy lol
<<<this car shows a ton of "knock retard" but it doesnt really pull much timing. you need to be able to see what the commanded timing is at the time the knock occurs. it could show 4* of knock but it may only pull half a degree of timing.
gm probably isnt really going to care what i have to say if they arent interested in fixing anything without a code.
i still go back to - if more octane makes it go away then i would find what works for you, a bottle of octane booster or mixing fuel or maybe e30 mix or get a custom tune to get rid of the knock

 

[smokey_mountain]

Thank you. Yes, I am trying to do everything to keep the truck. I just went for a long drive and logged again. While logs shows few KR events, up to 4 degrees. There was no audible pinging, same tank of fuel, same load, same route. What was different - the outside temperature, it is finally cold in NC, outside temp was ~42. I could not hear a single pinging event, before it was very audible. What sensors might be to blame here? I thought maybe active shutters on Tahoe do not open fully but temp gauge does not show overheating ever. Is MAF also a temp sensor?

 

[STORMIN08]

i can say this, in the warmer temp environments, mine has a knock with most pump gas fuel octanes. oddly enough, i recently swapped my 89 c1500 from FI to Carb, i am in the process of switching thermostats back to a lower level. reason being, 10* initial timing...32* total pings at heavy throttle with all fuels.

again, i do belive the higher temp needed to make efi perform, is to high for traditional carb applications. i am going to a 165, from a 190.

now, with the lower Missouri temps, the pinging on the 17 burb, is not noticed at all.