New to board and have a question in regards to pinging with a 2000 4.8l sierra.I have tried 89 and 93 octane with no success and took timing out with a predator but it still pings under load. Is there something else that would cause this besides timing? I have an airaid cold air and mit along with a throttle body spacer,exhaust and a throttle body hot water bypass on the truck. Any of your help or wisdom would be very appreciated. Please give me some ideas on what to do. Thanks

 

Could be running a little lean, or possibly carbon deposits. If you have a scan tool you can check out your long term fuel trims, if it's postive, it's lean. If that's OK, you could try doing a top end clean with Seafoam (not a bad idea to do as a maintenance item anyway)

 

Where can you get Seafoam from?

 

Try fuel filter first,lean conditions WILL cause detonation

 

Pinging as in audibal pinging? Or something you are interpretting as pinging on a scanner? 2000's are known for KR...but audible pinging is bad none the less. It defintely means too lean or too much timing. Any codes?

 

Sticking EGR valve if equipped comes to mind.

 

vacumme leaks can cause spuradic problems Im finding out about that now

 

I get it from NAPA.