cylinder 1 misfire

[destro77]

I had this reading on my 2007 Tahoe. Replace wires plugs and coil. Still problems. Had the head taken off turns out the lifter is stuck in the closed position. Now my options are new motor or send it to a machine shop. Anyone else had this problem?

 

[Chev454ss]

Sounds to me that it's time for you to do your heads. Depending on your miles you may want to consider just doing an all around freshening up of the motor. If you just have the heads done, you can have a slight increase in cylinder pressure which will lead to blowby on your piston rings. It happened to me once....only once. If I have a head problem I just pull the engine and tear it down, have the heads done, hone the cylinders, all new bearing, bushings, rings, etc. It's not worth the aggrivation to fix one problem and have that fix make you get back under it and pull it again later because you tried to save a few dollars. Good luck!

 

[gsxrkid]

I'm having this same exact issue with my 07 right now as we speak. Mine is Cyl 2. I've done plugs, wires, seafoam treatment, and had Justin from BlackBear do a custom tune to get rid of the stumbling idle/CEL problems (and of course better performance). Nothing has worked so far. Going into the dealership on Tuesday for its final diagnosis. I'm expecting valvetrain issues is the root cause as well. 94K on the odometer and I have babied this thing since I got it at 28K. Not impressed with GM right now.

 

[GM Customer Service]

gsxrkid,

Hello! I am sorry to hear that you are experiencing an issue with your vehicle. I understand that you are seeking technical advice on how to resolve this issue yourself. I might not be able to give you any technical advice but if you find you cannot resolve this issue yourself, I am happy to assist. Please private message me if I can be of any assistance.

Regards,

Jennifer T.
GM Customer Care

 

[gsxrkid]

Hey Jennifer, I tried to PM you but apparently I don't have enough posts on this forum to be able to PM people. I really do appreciate you guys taking an active approach at helping us out with issues like these. I ALWAYS try to go through the dealer whenever I have issues with my GM vehicles and I replace just about every part with GM factory parts. That being said, I would really appreciate any assistance you could offer but at this point my vehicle is out of warranty by both mileage and time. Is there really anything you can do? I stated that I had BlackBear do a custom tune and that is true. Justin is an absolute wizard with these engines and he showed me on the computer how when my Tahoe sat idling, the misfires just kept racking up until eventually there were enough logged to throw a CEL. He said that by the way it acts, it is almost surely a valvetrain issue. The more research I do, the more I see that others are having the same issue. I have an appointment Tuesday morning to take it in to my local chevy here in San Diego and I guess I'll see what they say. Do you have any advice or assistance you could suggest? I have taken absolutely superb care of my truck since I've owned it and I cannot believe that I would be having major engine issues already UNDER 100k! Thanks in advance.

 

[992dr]

From what I have been reading, the DOD/AFM is the culprit.
It seems to be the reasoning for that rough idle to.

Why not have a recall on this? It seems to be a pretty common problem.

Technology is not always a good thing.

 

[gsxrkid]

BB disabled my AFM and it still had the "chevy stumble" even after it was off. Justin turned up my idle 50rpms in park and 25rpms in gear and after everything we could still just sit there and watch cyl 2 misfire almost every other cycle. As soon as I accelerated off idle then the misfire goes away which is why he thought it was valvetrain, either a lobe that's worn down, a flat lifter, a bent valve or pushrod.. ect. If your having a misfire, its more than just the AFM.

---------- Post added at 07:46 PM ---------- Previous post was at 07:42 PM ----------

I absolutely agree with you though, it definitely seems like a lot of people have this misfire/stumble issue that makes it feel like WAY more than just mere coincidence.

 

[harveje]

+1 on stumble, miss but no CEL or misfire according to scan tool.

 

[destro77]

Truck still in the shop replacing all the lifters since its apart already. fingers crossed

 

[harveje]

Did you go with the delete kit or back OEM