2002 gmc savana 5.7l ses light

2002 gmc savanna 5.7 liter. For 45,000 mi the various dealers in San Diego have played with this. I get ses and low power on load up hill. dealer did mfi convert then replaced and cleaned injectors. (very first dealer replaced the radio. It did not work. I changed dealers.)

Then still had ses come on load and especially on downhill side. (strangely happens more often on cement than asphalt?). Dealer now recommends valve sticking on cyl 7. They did this under warranty.

Now in first 16 mi got ses. It goes on all the time.

Dealer is now suggesting low end problem with main bearings…

It sounds like the shop is guessing at the problem. Without knowing what code is being set we are left to doing the same thing. Can you tell us what code is being set?

Mom sed I shudda proof red this…

the dealer did a valve job. this was to free up the sticky valve. Now in 16mi get ses all the time.

the dealer now sez teh engine has lower end problems in the main bearings that might be causing timing problems.

In all cases the code is P0300 and sometimes P1381 n P3081. Tech has sed several times abs non communication


Code P0300 - Several Misfires detected.
Code P1381 - Not sure on this model, but could be a misfire detected, cylinder position sensor intermittent interuption, or variable cam timing over advanced. This would be a manufacturer-specific error code.

Has anyone simply suggested a tune-up? I can’t fathom a valve problem or low-end bearing problem with this code, but no associated noise, like pinging or knocking to back it up. I might suspect a problem with the crank sensor, but there are other codes for that. A tune-up and checking the coils for proper operation is where I would have started.