My engine sounds like it's pinging, only more muffled. Just started doing this yesterday. From just off idle(1200 rpm's) during even light acceleration and on the road whenever more throttle is needed. I don't think it's a fuel issue as I'm halfway thru a tank of gas and this just started. No SES light or any other symptoms that I can think of. Can anyone shed some light on this? Thanks, Dave
Sorry, .....1999 GMC 1500 Z71
Dave,
Sorry I don't have more info, but I have the same truck as you, 2000 though. I have dealt with an engine ping since day one (2001, 19k Miles). I have run premium fuel, changed fuel filter and pump and replaced every knock sensor in the engine. It still pings. It's worse at about 42mph Trans in OD and very light acceleration. You can hear the pinging inside the cab. I took it to 3 different dealers and none of them can fix it. They tell me it's normal. One dealer said that since the pistons were forged, excessive knock won't hurt anything. Another dealer said the premium fuel I used screwed up the computer and that's what caused it. I don't have the answer and I don't know how truthful the dealers are, but I am all ears from this point forward.
Derek
I do believe there is an updated PROM configuration that addresses this problem. I'll take a look for the TSB if one exists..........
Doc
As usual, Thanks Doc. I had the PROM flashed once already (1.5 years ago & dealer recommended) and that made the problem even worse. When I complained to the dealer, they said they can not reflash the PROM with an older revision and I am stuck with the firmware upgrade. Does that make sense?
Thanks again, Derek
Doc,
Thanks again. I have never run any of the fuel "additives" as I figure they are worthless. You seem to stand by Restore and this techron stuff. The techron is about $7/bottle, but if it reduces the pinging, then all is well. Thanks again for the advice.
FYI, I had a service mech ride with me with a tech II analyzer plugged in. When the pinging was the worst, the tech II showed 28 degrees timing advance. Seems high to me!
Derek
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