07 Yukon Stability/Traction Control issue

[Justatrucker]

Hey guys,
Been working on my wife's 07 Yukon, and just about ready to burn it, lol..
So about a week ago, it started idling a little rough, not bad, just sorta like a miss; not constant maybe every 15-20 seconds, and only at idle.
Otherwise it ran excellent, with no power issues.
I have three young boys, and didn't want her out with them breaking down, so I did a tune up;
Belt, air filter, oil & filter, plug wires, and new AC Delco Iridium plugs.
We took it for a drive that evening to my oldest sons soccer game about seventy miles away.
It ran smooth as can be and like the day it was new on the way there, and half the way home,
However about halfway home, the dash started dinging, the engine light, started flashing, the traction control light came on, as well as stability and traction control on the digital readout.
It is idling extremely bad, giving it gas is no better, i can hear what sounds like a peck or knock from the engine, and it feels and sounds like its only running on five or six cylinders.
I called a friend to come and get us, and went back with my 2500hd and trailer and hauled it home.
Got it in the garage, and have rechecked everything I did to it that morning, plugs, wires, etc, and everything is fine as it should be.
Have checked everything around he engine, underneath, etc, and everything looks perfect.
This car is in mint condition, been garage kept, you can literally eat off the engine.
Just turned 130,000, never once had an issue with this car.
Just cant figure out what happened, it goes from running perfect at 70mph, to running like a piece of junk, with lights, bells, and no power, in 2.9...
Checked the codes, and only one it has is the Stability/traction control..
Any thoughts or ideas would be greatly appreciated guys, thanks for your time..
Michael

 

[conchasjim]

Mine did the same thing last week. Stability control needs service, rough idle, but would run fine at highway speeds. Check engine light started flashing. So, I checked the codes, said cylinder 6 misfiring 600 times. So swapped wires and plugs with nearby cylinder. Same thing. I then checked that the coil was firing on number 6, and it was. I then cranked the engine without starting and notice an irregular pattern. Indicating a mechical problem to my way of thinking. I've been told it's likely a collapsed lifer or broken valve spring from a friend who's a GM mechanic.
Not sure where to proceed with this. Any else have a clue?

 

[Cavan806]

Mine did the same thing last week. Stability control needs service, rough idle, but would run fine at highway speeds. Check engine light started flashing. So, I checked the codes, said cylinder 6 misfiring 600 times. So swapped wires and plugs with nearby cylinder. Same thing. I then checked that the coil was firing on number 6, and it was. I then cranked the engine without starting and notice an irregular pattern. Indicating a mechical problem to my way of thinking. I've been told it's likely a collapsed lifer or broken valve spring from a friend who's a GM mechanic.
Not sure where to proceed with this. Any else have a clue?

Did you ever get anywhere with this issue? I am having the exact same problems right now.

 

[Cavan806]

Hey guys,
Been working on my wife's 07 Yukon, and just about ready to burn it, lol..
So about a week ago, it started idling a little rough, not bad, just sorta like a miss; not constant maybe every 15-20 seconds, and only at idle.
Otherwise it ran excellent, with no power issues.
I have three young boys, and didn't want her out with them breaking down, so I did a tune up;
Belt, air filter, oil & filter, plug wires, and new AC Delco Iridium plugs.
We took it for a drive that evening to my oldest sons soccer game about seventy miles away.
It ran smooth as can be and like the day it was new on the way there, and half the way home,
However about halfway home, the dash started dinging, the engine light, started flashing, the traction control light came on, as well as stability and traction control on the digital readout.
It is idling extremely bad, giving it gas is no better, i can hear what sounds like a peck or knock from the engine, and it feels and sounds like its only running on five or six cylinders.
I called a friend to come and get us, and went back with my 2500hd and trailer and hauled it home.
Got it in the garage, and have rechecked everything I did to it that morning, plugs, wires, etc, and everything is fine as it should be.
Have checked everything around he engine, underneath, etc, and everything looks perfect.
This car is in mint condition, been garage kept, you can literally eat off the engine.
Just turned 130,000, never once had an issue with this car.
Just cant figure out what happened, it goes from running perfect at 70mph, to running like a piece of junk, with lights, bells, and no power, in 2.9...
Checked the codes, and only one it has is the Stability/traction control..
Any thoughts or ideas would be greatly appreciated guys, thanks for your time..
Michael

Ever figure out what the problem was? I am having the same issue

 

[swathdiver]

Probably a collapsed AFM lifter for both of you. Time for a DOD delete kit, a cam and a Black Bear tune to turn it off.

But, always check the simple stuff first, have access to a Tech2? You'll know right quick what's going inside the motor with a good scan tool.

 

[Cavan806]

Well I found my problem. #7 misfire. went ahead and replaced all plugs and wires. Runs smooth as butter now.