Chevy uplander pinging issue

[greg24]

Sorry guys this is my first post, i had no idea where to post this. Anyway, we have a 2005 Uplander with the 3.5 v6, and it just crossed 100K miles...we do oil changes at a local shop every 3000 miles with regular dyno oil. I think its castrol gtx...anyway, ONLY AFTER then car heats up to operating temp and you are accelerating right around 2500-3000 rpm (thats where the greatest load is on the engine) it starts to ping (that marbles in a tin can sound) yes we started to use premium 93 octaine gas, yes we have done a carbon clean out and used seafoam and techron multiple times. had the coolant changed too. new spark plugs and wires also. NO check engine lights ever. had it scanned, nothing. Is this damaging the engine? Ive heard pinging is bad for an engine. Its been going on for about a year and a half. it doesnt happen during the winter months though. we live in florida so the winter months are very few. SO most months it is pinging, and in the summer when its hot out it pings VERY bad. Any idea? is there bad damage being done? or is she going to be ok? we want to keep the van for a while longer, just had the transmission rebuilt and two new tires put on the front as well as a rear brake job.

 

[zora]

Do you always buy gas at the same station or does it happen no matter where you fill up? Have you tried disconnecting the battery for about 10 minutes in order to do a "reboot" of the computer? There is a service bulletin below and another one concerning knock sensors but it throws a code. Has the vehicle been checked by a GM dealer?

Service Bulletin No.: 060601014
Component(s): ENGINE AND ENGINE COOLING

NHTSA ID Number: 10021117

All Products Associated with this Service Bulletin

Details

0 Associated Documents

Manufacturer: General Motors LLC

SUMMARY:
L36, L67, L26, L32, LA1, LX9, MN7, M15. TICKING OR KNOCKING TYPE NOISE COMING FROM THE ENGINE OR TRANSMISSION AREA. *KB