2001 silverado 6.0, ran fine this morning, then stopped at store , when I started it it was missing, would not go over 15mph, was rattling the valves very loud, pulled over, turned it off for few minutes started it and it was fine, then started chugging again, did this 3 times, fuel pressure good, no codes, any help?

This message has been edited. Last edited by: fast frank,

Mine went into reduced power mode once, check engine light flashing, was able to creep home at 15 mph or so, luckily very close to home. My MAF had come loose from the tubing leading to the engine........

I had an issue years ago when the plug wires went bad and were arcing.

Other than that, 140K, no issues.

If you heard the valve train rattling to me that is not a good sign. Heard of oil pump pickup tube issues, wonder if you have a problem there.

removing the positve and neg cables from the battery and clamping them together will clear the code.

quote:

...was rattling the valves very loud...

Wonder if that could have been detonation?

not a tech,but have been through that more than once,it sounds like something put it in limp mode.

quote:

Originally posted by B.C.Malibu:
removing the positve and neg cables from the battery and clamping them together will clear the code.

was that for me? has no code

It will reset and clear limp mode