2016 Silverado 5.3 6 speed shutter, misfire, chuggle on accelerator tip in

nluchau · July 17, 2021

I just started noticing this after an 1100 mile trip. A little history: Transmission and Torque Converter replaced at 35k. All updates done.

After operating temp is reached on vehicle and from a stop. I accelerate until it hits about 4th or 5th gear (typically 40mph) and then do a tip in of the accelerator to increase speed although I don't want it to upshift. I notice its almost like a misfire or chuggle feeling like its starving for fuel. That is until I kick it down and it upshifts and then it won't do it. Just does it under light throttle tip in. The trans fluid is nice and red, I replaced the air filter and put a bottle of techron in for now and topped it off with 91 octane.

It only seems to happen once at operating temp. No check engine light. Just curious if others have experienced this and what the solution was? On that 1100 mile trip I had to fill up a few times using 87 octane since I could not find 89 that I usually use. I am hoping it could be bad gas but not totally sure. Any ideas greatly appreciated.

rlcole321 · July 17, 2021

5th gear at 40 mph is barely 1,000 rpms, and it is probably in 4 cyl. mode, and the converter is at that point of lock up. It's like driving a manual in high gear at 1,000 rpm. now if you have a slow reacting lifter coming out of it's "cancelation" mode, that might explain it also. I have a 18 5.3 and notice a little (high gear / low rpm / 4 cyl. mode) chug until it goes back to 8 cyl. mode.

nluchau · July 17, 2021

3 hours ago, rlcole321 said:

5th gear at 40 mph is barely 1,000 rpms, and it is probably in 4 cyl. mode, and the converter is at that point of lock up. It's like driving a manual in high gear at 1,000 rpm. now if you have a slow reacting lifter coming out of it's "cancelation" mode, that might explain it also. I have a 18 5.3 and notice a little (high gear / low rpm / 4 cyl. mode) chug until it goes back to 8 cyl. mode.

Thanks for the reply rlcole321, I am using a range so its kept in V8 the whole time. I get what you are saying about it hanging around that 1k rpm mark and you are correct. Once at that point in 4th or 5th gear and I tip in to accelerate I notice the chuggle. Knock on wood I never felt it so far today yet after filling up with 91 octane. I did clean the throttle body today too. I'll report back if it continues to occur once running 91 through for a while.