Clean MAF and throttle body, then Tech 2 relearn idle on 2013 Escalade 6.2L

[skpyle]

The last thing I needed to do before I could datalog for the Black Bear Performance tune was clean the MAF and the throttle body.

I was forewarned by the service manual that I would have to either perform the Throttle Idle Relearn procedure via a Tech 2, or let it relearn on its own. Luckily, my new Tech 2 showed up.

I carefully removed the MAF sensor from the air horn on the air filter box by removing the two T15 Torx head screws. Yeah...I know this is simplistic, but I was paying attention and didn't want to drop either screw. And I didn't want to screw up the MAF. The MAF came out no problem. Sensing wires and IAT resistor were in excellent condition, as was the sealing O-ring. Cleaning consisted of gently spraying both sensing wires with CRC aerosol MAF cleaner, then letting air air dry for awhile. Wipe off the O-ring, reinstall the MAF into the air horn, and call it done.



MAF mounting point in the air filter box air horn.




MAF, sensing side up.




Sensing wires and IAT resistor.




Only cleaning tool needed.




MAF back where it belongs.

 

[skpyle]

MAF sensing wires in the air stream of the air filter box air horn.



Throttle body cleaning was more involved, but not difficult. I have read threads and posts on the internet both ways about cleaning the throttle body in place or removing it. Service manual recommended removing it, and I am good with that. Removed the electrical connector then two 10mm headed nuts and two 10mm headed bolts. Throttle body pulled right off the two upper studs and went into the work shop.



Throttle body has some miles on it.




Gaping maw of the intake manifold. There was light oil residue and carbon coating the inside of the intake manifold. I am assuming it is from the PCV connection to the intake tube. I could not feel any liquid oil, just residue. I wiped it out as best I could with a brake cleaner soaked rag.



Rag after cleaning inside of the intake manifold.

I have read about oil injestion and catch cans needed for earlier 5.3/6.0/6.2L engines. However, I thought most of the issue had been resolved by 2013. Based upon the oil film I saw in my intake manifold, I don't think I need a catch can.
What say you?



Throttle body assembly, waiting to be cleaned.

Note: I did NOT remove the cover over the gearing and electrical side of the throttle body. I saw no reason. Everything worked fine, no need to disturb a sleeping beast.

 

[skpyle]

Oil and carbon residue at the top of the bore.



Oil and carbon residue on the back of the blade and in the bore.


The cleaning tools consisted of a can of CRC aerosol Throttle Body And Air Intake Cleaner and a lowly toothbrush. I had a can of SeaFoam standing by. The service manual calls for GM Top Engine Cleaner to be used as solvent for cleaning the throttle body. In my experience over the years, SeaFoam is very similar to GM Top Engine Cleaner. I ended up not needing the SeaFoam. The CRC stuff worked just fine.

I cleaned the bore and blade through a combination of spraying directly on them, spraying on a rag and wiping, and spraying on a toothbrush and scrubbing. The residue came right off without much of a fuss. I don't know how bad these engines dirty up the throttle bodies, but I don't think this one was too bad.



Tools of cleaning.




Cleaner than before.



Much better.

 

[skpyle]

I reinstalled the cleaned throttle body with a new gasket. It probably did not need it, but the service manual said to replace it. So I did.
(Note: I am still new to 'late model' GM, so I don't have the experience with them to tell me what can and cannot be gotten away with.)

Installation was simple and straightforward. However, in a bit of OCD paranoia, I installed the nuts and bolts and tightened them with my fingers. Then, with a nut driver, ran them all down by hand in stages. Then I torqued them to 89 inch/pounds. Point of all this was to evenly compress the throttle body gasket in its groove in the intake manifold.




New ACDelco 125889235 throttle body gasket at left, old gasket at right.




Cleaned throttle body back where it belongs.



Next step was the Throttle Idle Relearn procedure.



Tech 2 and Candi module in use.



Tech 2 screen for Throttle Idle Relearn. Note Reset soft key.


And..it worked!!!


I started the engine cold, it hit high idle of 1200RPM, as commanded. It then dropped down near commanded idle of 664.
Success!




However, I did not drive it. I will drive it to work tonight. I don't fore see any issues.

 

[Doubeleive]

nice, 99% of the time though no relearn is required, only if it does not idle properly on it's own afterwards
other things you can add to this is a new air filter and a injector service or throw some injector cleaner in the gas tank for a few rounds that helps smooth out the idle.

 

[donjetman]

I didn't have to do the re-learn when I cleaned the throttle body.

 

[Foggy]

I always replace the throttle body gasket... I'm sure some of the time it wouldn't matter...
but I'm ocd that way too

 

[skpyle]

nice, 99% of the time though no relearn is required, only if it does not idle properly on it's own afterwards
other things you can add to this is a new air filter and a injector service or throw some injector cleaner in the gas tank for a few rounds that helps smooth out the idle.

Thanks. I did not know that. I had visions of 3000rpm idle.
Air filter was replaced when I bought it. I have been running 2 cans of SeaFoam in each tank of fuel since I bought it. I will back down to every other tank soon.

I didn't have to do the re-learn when I cleaned the throttle body.

I wasn't sure what to expect.

I always replace the throttle body gasket... I'm sure some of the time it wouldn't matter...
but I'm ocd that way too

I understand.


Escalade drove fine to work tonight, no issues at all. In fact, while datalogging for the Black Bear tune, I found that there is a speed limiter at 107mph...

 

[Doubeleive]

Thanks. I did not know that. I had visions of 3000rpm idle.
Air filter was replaced when I bought it. I have been running 2 cans of SeaFoam in each tank of fuel since I bought it. I will back down to every other tank soon.




I wasn't sure what to expect.



I understand.


Escalade drove fine to work tonight, no issues at all. In fact, while datalogging for the Black Bear tune, I found that there is a speed limiter at 107mph...

they can turn that off for you then she'll do 140, maybe a little more if you are lucky and have enough runway.

 

[skpyle]

they can turn that off for you then she'll do 140, maybe a little more if you are lucky and have enough runway.

Sweet. I was kinda thinking about that...
I know she hit over 100 faster than I expected.