alvocado

You have three variables: air, fuel, spark. Based on the quick start with the pedal comment, I would focus on fuel delivery first. Put a gauge on the fuel rail.

12585328

The 5.3L. I had limited sight with the mirror and if there are tabs to grab, I must have missed them.

I replaced my oil pressure sender this evening on my 2011 Yukon and could not see or feel the filter. I did not remove the intake so I was poking around with a finger and using a small mirror against the firewall. I eventually gave up and installed the new sensor without removing and cleaning the filter. How deep are these filters and what's the trick for pulling them out?

As @txab says, dye is available for both oil and coolant to detect leak sources. That would be the most efficient and cost effective way to track down the source of both issues.

My torque converter failed on my '11 Yukon 3 weeks ago and the symptoms were similar with RPM jumping, trouble finding and staying in gear and for the prior couple of mos., a noticeable hard clunk on downshift from 2nd to 1st when coming to a stop. Your stabilitrak error is a separate issue. If your TC is failing, you will need a rebuild. You have metal fragments throughout your entire system including the radiator and trans cooler/cooler lines that will need to be flushed with special equipment. It's not a simple diy and will require TCM coding if you swap in a different rebuilt unit. Find a reputable transmission shop to handle a rebuild and ensure they upgrade components to address known failure items. I paid $4300 for my rebuild.

Yes, it was the torque converter. It's being rebuilt now and it's loaded with metal frag.

Apparently imminent failure is expected. The transmission shop where mine is headed said they do 20+ 6l80 rebuilds per month.

I'm curious how many miles folks are getting out of their 6l80 transmissions. I've maintained my 2011 Yukon from new with 50k mile transmission fluid and filter changes and it just left me stranded 300 miles from home at 219k miles on the odometer. No warning signs until the day of the trip when it started clunking a bit then wouldn't shift at all when getting back on the highway. I managed to get it to shift into fourth gear for a 3 mile drive to a dealership lot off the highway where it sits, 5-1/2 hours from home.

I didn't think the gears were engaged if the truck is in 2WD (not auto mode), only the output shaft rotates because it's attached to the CV axle. If just the shaft is moving, I would think it's a bearing. I did cycle through full time 4WD mode but no change.

My 2011 GMC Yukon with 216k miles has developed a clicking noise coming from the driver side output of the front differential. It sounds like tire noise while driving so I pulled the wheel and disconnected the CV axle at the diff, spun the diff flange and the noise was confirmed to be the differential. I've done 50k mile gear oil changes so the gears should be in good shape. Despite being very mechanically competent, I don't have any experience rebuilding a differential. For those with experience, is this likely the output shaft bearing and is it worth finding a driveline shop to rebuild vs. sourcing a used assembly? I'll have to pull the diff out myself and drop it off if I go the driveline shop rebuild route and will be down for a week waiting on parts after the shop tears the assembly open. I did have a GMC dealer rebuild a front diff on a Yukon about 14 years ago but I doubt they see many of those jobs.

I'm having an issue with excessive outer tire wear on a 2011 GMC Yukon despite the alignment checking within factory spec. I changed both front lower control arms in June and had the truck aligned the following day. Arms were installed per factory set, torqued at ride height. Two mos. later, the outer edge of both right side tires shows noticeable wear and is causing increased road noise. I took the truck in today and the alignment still reads within spec. Struts are Bilstein with <100k miles. All other components are factory with 213k miles on the truck. Any advice from others who have seen this or knowledgeable of alignment would be appreciated.

I bought a complete set of OEM sensors from TPMS.com years ago and had no issues. They sell the OEM supplied units at prices much less than retail or tire shops. I had the tire shop install them when I bought new tires so there was no additional charge.

If you have a scanner that can read GM diagnostic codes (some Actron scanners do) you'll get more specific info on the issue. I had the same problem and the GM code pointed to a faulty 4wd selector switch on the dash. The terminals on the back of the switch become corroded and send incorrect ohm readings to the 4wd shift module. When the drive setting doesn't match the signal, you get a service stabilitrak error on the dash. The selector switches are inexpensive and easy to change out.