TOPIC: 2011 6.0Liter GMC Savana

Hi Folks

I grooved a 2011 6.0L GMC Savana everything went good easy access other than pcv line here I had to removed to cowling over the engine inside the van between the front seats whiched is not hard to do just a little annoying. This is a work van I drive personally to job site and back. It was averaging around 17-18 Liters/100 kms which I believed is about 13 mpg, it has been improving little bit at time tonight I got to 13.6 Liter/100 kms (17 mpg)it has better power useage now shifts smoother, hangs in gear longer before downshifting, and it has a whistle the boys that were with me wondered what going on (it was my secret) but the cat is coming out of the bag now the proof is there.

Happy Grooving Everybody

Aaron Knorr

PS This is a electronic throttle body unit lots of meat for the groove but it sits rigth out at the edge (just watch that part when cutting groove)

Good job looks like your on your way. dan gadgetman mo.

This is really impressive, Aaron!

30% increase in mileage! Way to GO!

PLUS ONE FOR KARMA!!!

Now, did you fill out the Modification Report Form? I hope so!!! This is the best way we have to validate our increases, as it is a written record. Also, you use that as the basis for your online reporting.

TO EVERYONE that reads this: FILL OUT THE MOD REPORT FORM ON EVERY MODIFICATION!!! It will help you TREMENDOUSLY as time goes by. After filling out about 800 of these myself, I can tell you I use them frequently to reference not just the changes, but to keep up with my customers!

Hi Guys
This van gone back to an updated throttle body and no groove , on the way home from work the stabilitrac light and chimes of all sorts and a reduced engine power message came on the dash, the motor felt like it was running on 2 or 3 cylinders and ready to die on me. Turned the key off and waited little bit 5-10 min. started it up and drove home like nothing was wrong. Next morning drop in at the GM dealer explained what happened and he recomended that I leave van there, he seemed to know what was going on said the tps was the problem, (he said they did 25 of them in the last 2 months). I picked van up the same day and asked if that was the problem, he told me they replaced the whole throttle body, I asked why he said there were two codes that came on one of them being the tps the other he didn't want to tell me and claimed if that happens they just changed the whole unit I couldn't get more info out of him other than he said something about mositure which didn't make sense to me. Mind you guys I push him pretty hard to find out, I even told him it doesn't relly make any sense because a basic throttle body has a tps on one side and a motor to run the butterfly on the other side. I talked to my boss about this and he wants to run like this for a little while for now and see what mileage I will get.GRRRRR

So that my story on that, I'm going to try and get this throttle body grooved too sometime.

Aaron

Hi Aaron,

I've posted about this on other recent threads but this is a good one to repeat on.

The "Stabilitrac" system that General Motors has been pushing out on all their vehicles has been having issues from day one.

In most cases it starts showing itself at about 50,000 miles, there are issues reported about brakes locking up, performance taking a hit and in my case and it sounds like yours too... the engine shuttering to the point that you will find it in pieces on the ground.

Typically there are no codes generated when this happens and when you shut off your engine, wait a bit and restart it the problem resets itself.

One person reported that there is a sensor in the steering column that was replaced on his vehicle, many others have had a number of items replaced including injector coils, spark plug coils, O2 sensors, the list goes on but they have no real answer, they are simply throwing parts at the problem hoping one of them fixes the issue.

I have found that on my Avalanche, I can get this to occur more frequently if I plug the OBDII scanner into the port.

One event occurred coming back from Eastern Washington, over the pass at 75mph. According to the computer, right before the Stabilitrac flag popped up I was getting 25mpg... Tell me the MAP wasn't having some serious issues there!

I haven't seen that code in at least three months but I haven't been messing with the throttlebody either.

I'm getting a city average of 15+ and a highway average as high as 20mpg and thanks to GM's ECU and programming it does fluctuate.

Karl Fortner
Tacoma, Washington

What happened is not uncommon. Chev throttlebodys have a tendacy to sweat and freeze and if you try to start and it hesitates even for a spit second will go into limp mode,sometimes off and restart will reset not always. Sometimes you will need to reset code or undo batt cable.

Has nothing to do with groove I`ve had many do it with no mods. When the engine is shut off and moisture is on tps from sweat it causes a slight drag.

Sounds like these new DBW TBs have no coolant jackets. I can easily understand how a poorly sealed electronics housing could cause skewed signals the ECU would panic over. A bit of humidity, some cool temps, high pressure drop across the throttle plate, BAMMO!

Sorry to hear someone stole your Groove, though.

Mike

I think you may be right Mike, I can't beleive that it didn't happen to the other work vans yet being there are 7 of them in the whole fleet all with the 6.0 L engine in them. I'm already noticing an decrease in the fuel mileage and it is not as responsive on the gas pedal (which pretty much all the gadgetmen groovers know) hopefully with time I can persaude the boss the regroove this vechile again.

Aaron

What do ya think went thru the service managers mind when the tech showed him the Grooved TB?

Karl Fortner
Tacoma, Washington