Dealer not honoring warranty work..2018 5.3 Yukon issues

[BG1988]

I was reading the bulletin.

https://static.nhtsa.gov/odi/tsbs/2019/MC-10163272-9999.pdf

There doesn't seem to be anything that voids the warranty by just using a reader. But, I don't think I would disclose to the dealer/GM that I was using any other device.

What is seen in the bulletin is people were dumb enough to take their vehicles into the dealer and leave stuff plugged into the OBD. I don't think GM has programmed the ECUs to track when a device access the port.

i'm pretty sure that would be pretty hard to prove that it caused damage it might even be illegal

 

[91RS]

High resistance in a battery cable is not going to cause a fire...

It’s ridiculously easy to prove a device plugged into the OBD is causing problems when it’s unplugged and the problems go away...

 

[smokey_mountain]

The truck is with the dealer, they are doing mounts TSB, I am paying for this TSB to be performed, dealer promised to do this TSB to a T and reseat both engine and transmission. My decision was to run to the end of the rainbow as I hate to take a loss on it. My fingers crossed...

 

[cesarqjr]

Looking forward to the results. My 2019 LT with 48k miles is exhibiting the same symptoms.


Sent from my iPhone using Tapatalk

 

[smokey_mountain]

I owe this forum my update... after 4 days in repairs my truck is back with brand new mounts all around and ... $1100 down the drain. No improvements. Same rough idle, but, of course, all within the GM spec.
I wanted to thank everyone on this forum for camaraderie and support. I ran to the end of the rainbow and there are no unicorns there.

Bottom line:
1) new plugs or wires did not change a thing
2) mounts did not cure anything

Original troubleshooting done by an independent GM tech was pointing to a faulty injectors but given no codes, I do not think I can do anything about injectors. Time for my plan B.

 

[dnt1010]

You cannot give up, you must persevere and find the actual problem for the sake of the forum. Please proceed with having the injectors replaced. it is only money...................... (I love spending OPM)

 

[smokey_mountain]

True only money, that is why Koreans got them this afternoon. Wish I could spring for a Japanese again but GM got most of my budget at this point Toyota is out of my reach.

You cannot give up, you must persevere and find the actual problem for the sake of the forum. Please proceed with having the injectors replaced. it is only money...................... (I love spending OPM)

 

[HiHoeSilver]

True only money, that is why Koreans got them this afternoon. Wish I could spring for a Japanese again but GM got most of my budget at this point Toyota is out of my reach.

Appreciate the follow up and closure. Gotta say it, though...I can't believe that after all that, you didn't just tune that thing!!!

 

[smokey_mountain]

I bought BB kit was ready to tune but it occurred to me if out of 9 similar 5.3 trucks I drove 7.5 exhibit perfect idle even at 490-500 RPM, tuning will just mask the problem when this truck runs correctly it runs well even at designed 500rpms when truck misfires it will misfire even at 600 RPM I revved the engine to 600 and still felt the misfires. My misfires are very obvious and not subtle, everyone who sits in the truck feels them right away, no doubt about it. This is not a low idle situation, this is a clear misfire somewhere in fuel or maybe in the ignition coils. Who knows at this point...

Appreciate the follow up and closure. Gotta say it, though...I can't believe that after all that, you didn't just tune that thing!!!

 

[SnowDrifter]

Long ass thread, not going to read 25 pages. So sorry if I'm repeating anything

I'm wondering if it's cycling back and forth between lean and rich, and misfiring on lean. And you might have an injector that's underperforming to the point of misfire. Either rich or lean. Not sure what the GM spec on it is on the new rigs but I seem to recall reading somewhere a while ago that the tolerance for flow on older rigs that +/- 15%. I'm unable to locate that at current to take that with a grain of salt.

Sooo, my thought is this: See if you can find a good scanner. Figure out which cylinder is misfiring, if it's even tripping the misfire monitor. Cross reference that with the commanded fuel flow and/or oxygen sensor voltages.

If possible, see if you can tune or otherwise command the rig to run a bit rich to see if that alleviates the issue.


You might also try investigating your spark plug gaps. Narrow them down a few thousandths. See if there's some weird intermittent weak spark