2016 Yukon hesitation on acceleration - no codes

[ses_yukon]

Have a 2016 Yukon with the 5.3L motor, 150K mikes.

Starts fine, and idles fine, but hesitates when accelerating. It also slightly sputters when giving it gas in park. No issues with stalling. No codes with an OBD reader, no CEL.

Also when accelerating it sounds very tinny and like the RPMs are high, but they’re not according to the tach.

Cleaned the MAF, no change. Added SeaFoam to current tank of gas, no change.

Next step is plugs and wires. No idea when they were changed last.

I’m really concerned about a potential AFM issue. Any ideas?

 

[lbenson]

Would start with plugs and wires.. replaced them at 175k on my last Yukon (15 with 6.2) and it made it much smoother even at idle. If they hadn't been replaced at the recommended interval (think 97.5k) they could be the culprit. Pretty cheap fix and if it doesn't fix it at least you got new plugs and wires.

Unsure if it would be lifters. Would think you would hear some knocking maybe... and if bad enough would have a code. Just my two cents.

 

[ses_yukon]

UPDATE…

Well in my case it was the beginning stages of a transmission failure. It wasn’t hesitation, it was slipping.

I big shout out to GM for ignoring the issues of their 6 speed transmissions. I was hoping to drop $5K on a rebuild.

 

[SuperOldSchool]

But you said it hesitates when revviing in Park too - is that trans related?

On my 2015, if I goose it in park, it kinda stalls for a quick fraction of a second. Almost like it’s getting not enough fuel. It’s always done that as far as I know. May due to the idle being set to low?

 

[Doubeleive]

UPDATE…

Well in my case it was the beginning stages of a transmission failure. It wasn’t hesitation, it was slipping.

I big shout out to GM for ignoring the issues of their 6 speed transmissions. I was hoping to drop $5K on a rebuild.

that's pretty typical for a 6l80, they are known to start needing repairs around 120k. sometimes sooner sometimes later. the 8 speeds on the other hand are known to have lots of problems at any mileage

 

[ses_yukon]

But you said it hesitates when revviing in Park too - is that trans related?

On my 2015, if I goose it in park, it kinda stalls for a quick fraction of a second. Almost like it’s getting not enough fuel. It’s always done that as far as I know. May due to the idle being set to low?

I don't notice it anymore. However I did run a few cans of Seafoam through it. Maybe I had 2 issues but the transmission took priority. I imagine I could still use plugs and wires but after the trans, new pads and rotors all around and oil change I'm tired of messing with this thing for a bit.

 

[SuperOldSchool]

Yeah I get it. It’s frustrating.

I did wires and plugs at 76k. They looked good - posted pics in this site.

It seemed to run more smoothly after that, but could be placebo effect.

 

[kentman]

UPDATE…

Well in my case it was the beginning stages of a transmission failure. It wasn’t hesitation, it was slipping.

I big shout out to GM for ignoring the issues of their 6 speed transmissions. I was hoping to drop $5K on a rebuild.

Same here. Just dropped $5700 today after rebate for a replacement transmission.

 

[GeoffM]

Kinda sounds like how the injectors started to go on my '16 6.2
But if you successfully ran a few tanks of seafoam through it you might've cleaned them enough to keep going.