Rough Idle, Shuddering, and DTC

[PCBeachBum]

Took delivery of my white ZR2 on 11/14.

Since then I had the dealership install the GM Borla Exhaust and the kicker sub. Also had the windows tinted and did some mods at home, tonneau cover...etc. Honeymoon phase was going great, had about 1,000 miles on the truck with all but 200 miles being local small town driving/miles.

Over the last week or so I had noticed what felt like shuddering/jumping while cruising along while anywhere from 25-60MPH while at a low rpm. I was hoping that the engine was just relearning a few things after the exhaust swap and maybe it was DFM related. Late yesterday pulling up to a vendors place I noticed a rough idle. Did some googling and apparently a rough idle on the 6.2L is often brushed off as normal but mine had been butter smooth until that point so I knew that wasn't the case for me. I also knew though without a DTC I would probably be told it was normal.

I have done enough wrenching in my life that I knew in my heart it is a misfire. Cruising home about an hour later check engine light comes on and myChevrolet diagnostics immediately texts me to bring my truck in to "Service The Emission System." I start to hope on the way home that I was wrong about the misfire and maybe someone did something wrong on the exhaust install and it really is emissions related. Get home and pull the code.... DTC P0301 - Cylinder 1 Misfire.... good times.

Have an appointment for tomorrow morning. Question to you all is, do I drive it to the dealer? I am guessing that any damage has already happened. Dealership is about 10 miles away and there in no bad lifter knock, so maybe I'll get lucky and it's just spark or fuel related.

Loved the first 1,000 miles and hoping that maybe there is still a simpler issue than lifter replacement but we'll see.

 

[franky16]

is the check engine light on solid or flashing

 

[PCBeachBum]

is the check engine light on solid or flashing

Steady/Solid on.

 

[franky16]

I would drive it

 

[dedtoof]

I drove my 2021 5.3 trail boss in about 10 miles to the dealer with the same symptoms. It misfired but I don’t think it caused any extra damage. It ended up being the lifters. My ZR2 better not have the same issues.

 

[ZR2DARKASH]

Any updates on this, just got my 2023 ZR2 Silverado and drove it home 300 miles currently at 450miles and noticed the rumble/torque converter feel at low acceleration between 30-60mph. Truck threw a check engine light, app said engine transmission but it seems negative battery was slightly loose. All i did was remove, and retorque and check engime light is off.

 

[PCBeachBum]

Any updates on this, just got my 2023 ZR2 Silverado and drove it home 300 miles currently at 450miles and noticed the rumble/torque converter feel at low acceleration between 30-60mph. Truck threw a check engine light, app said engine transmission but it seems negative battery was slightly loose. All i did was remove, and retorque and check engime light is off.

Mine was the dreaded lifters. I am scheduled to get the truck back today or tomorrow.

My understanding is that GM has once again changed up the lifter replacement policy. For awhile if you had a lifter issue before 8000 miles they would replace all lifters(both banks). They have now gone back to replacing just the lifters on the bank with the failed lifter. I talked to my tech and know some of the guys at my dealership, they checked my cam and everything else and it all looked good. Apparently the lifter can fail in 2 positions thanks to DFM, one is way more catastrophic than the other.

I'm planning on getting the truck back and driving it just like I was before the code. Any more signs of powertrain issues though and I'll probably start shopping. Had this happen on a Wrangler back in 2012, Jeep had to pretty much rebuild the entire engine with 4k miles on it and it was never the same after. Swapped it for a 2014 with the same exact powertrain and that jeep has never had an issue and is still running strong.