2011 Yukon Denali 6.2 Flex issues

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Quick503

TYF Newbie
Joined
Mar 4, 2025
Posts
1
Reaction score
2
I bought a well-cared-for Yukon with 167,000 miles on it about four months ago. It has run great until now. I hope someone can help me with a couple of issues.
1. The cruise control has only worked a couple of times and won't work again after I touch the brakes. The light on the steering wheel switch comes on but not on the speedometer except for the few times it worked.
2 Sometimes the traction control light and check engine light will come on on startup, but if I turn off the traction control and then turn it back on, the light will go off, and after a few minutes, the check engine light will go off also.
3. Here is the serious problem. Yesterday we went to the big city (Texarkana, AR) to look at some antique shops. We were in there about an hour or so. When I started the engine, it bucked and sounded like it was going to come out of the hood. Big clouds of oil smoke billowed around the car. But here's the really weird part ... It smoothed out after about 3 minutes and the smoking stopped. It ran perfectly before and after that. Until this morning. I just went out to start it and same thing, bucking and smoking until it cleared itself out. It had not been burning oil before and I don't think it is now judging by the dipstick. Although I haven't checked it since those 2 events. Oil is seeping into the cylinders somehow. I have noticed what sounds like a lifter ticking very lightly but only when the car is in park and I hold the rpm at about 1500.
I'm 71 and have worked on cars and built engines since I was about 16, but I have to admit as cars became more computerized I enjoyed it less. There is something honest about a carberator.
Anyway, any help you can give me is very much appreciated.
 

Foggy

Full Access Member
Joined
Jul 25, 2019
Posts
1,184
Reaction score
1,544
Location
KS
Post up the year, engine, transmission, etc specs on your Yukon
for better help on this !
 

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
3,555
Reaction score
4,399
1 is the brake light switch

2 you'll probably need a scanner they can read chassis codes for they one. without it, it's just guessing.


3. do you happen to be losing fluid in the over flow bottle? is the white smoke coming from under the hood out of the exhaust?
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
20,150
Reaction score
27,468
Location
Treasure Coast, Florida
As to the major issue, she might have dropped a valve or have a partially collapsed lifter. The rocker cover has to come off so you can look around for the offending cylinder.

Better yet, put a bi-directional scan tool on it. Gotta get the codes and look at the failure records.

For the brake switch, use GM parts, takes about 5 minutes to swap out. Cleaning the terminals just kicks the can down the road.

D1539J or 25981009 - Both part numbers on the same box or bag.
 

Joseph Garcia

Supporting Member
Joined
Aug 2, 2018
Posts
7,855
Reaction score
10,850
Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.
 

petethepug

Michael
Joined
May 4, 2016
Posts
3,430
Reaction score
3,856
Location
SoCal
Big white billowy smoke thing occurred on my 09 6.2L. It was running e85. Thought it was a head gasket or I had backed over a sprinkler in the shrubs and it was steaming off the muffler.

A few days later I finally got a code for a bad crank position sensor and the tach didn’t work. Three month later it hasn’t come back but ordered the new OEM GM cps to replace.

The brake light switch will hopefully cure the CC issue. Definitely purchase a tech2. Just Google it and expect to pay about $250.
 

Forum statistics

Threads
133,847
Posts
1,892,245
Members
99,208
Latest member
Gordo816
Top