2015 GMC 2500HD misfires only at idle
#1
2015 GMC 2500HD misfires only at idle
So I took my truck in for a misfire code and was talked into basically rebuilding the whole top end, i.e. lifters, cam, oil pump, water pump, head/intake gaskets, plugs, etc.. He did show me the plug that came out of #2 and it was shot, after I'd only had maybe 15k mi on iridium plugs. Just got the truck back and its running rough at idle after the engine warms up. The engine will drop to around 500RPM and just barely stay running. Took the truck back to the mechanic who says got a consist misfire of #2 (had it hooked up to a scan tool). He says he did a compression check and # 2 has low compression and now needs a new block! If you give the truck gas it never hesitates and doesn't seem to misfire when driving (have go 80mph+ with no hesitation) Seems to me if the truck has low compression it should have a steady misfire from the start? Any thoughts? Ideas? I'm not ready to drop a new engine in this thing!
Thanks for the advice!
Thanks for the advice!
#2
Senior Member
True Car Nut
It sounds like the mechanic didn't diagnose properly before suggesting rebuilding the whole top end.
What are the compression numbers?
How was compression tested?
How many miles on the car?
How many miles have you owned it?
What are the compression numbers?
How was compression tested?
How many miles on the car?
How many miles have you owned it?
#3
The mechanic just said #2 had no compression. He added oil to the cylinder and the compression came up. So he thinks stuck rings. I'm doing a compression test on it today.
the truck has 145k. It only misfires at idle. Seems like rings would cause issues all the time
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05-14-2020 08:23 AM