What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[gpracer1]

Finally washed it on the way into work real quick.

Anybody have a clue why GM would have programmed these things to turn the AC off when engine braking in first gear?
That's pretty damn annoying when it's 100° outside.

Do you mean turn the entire AC system off, or just the compressor off for a moment?
My guess is that high rpms are sucking down the low side causing it to cycle off. If you mean it shuts if off completely then I would assume for compressor protection due to high rpms?

 

[RooTBeeRthe1st]

Do you mean turn the entire AC system off, or just the compressor off for a moment?
My guess is that high rpms are sucking down the low side causing it to cycle off. If you mean it shuts if off completely then I would assume for compressor protection due to high rpms?

Sorry, Compressor.
Doesn't do it at the top of 2nd though.

 

[89Suburban]

Tried the upper engine soak yet just in case it's a stuck ring(s)?

Does doing this f~up your cat's or sensors? Piss the neighbors off?

 

[iamdub]

so, i did comp and leak down when i got it, it was decent.
used 1qt in 5,000mi
now 55k later, its more than double the consumption...not a lot in the catch can either.
but when the blower goes on, im sure itll only get worse and be leaking horsepowers.
i might do another comp and leakdown before i yank it(doing a cam/springs, vvt delete, and dod delete) just for curiosity.

I guess the bright side is that, since it sounds like it needs new rings and a hone (as you've already determined), you could gap the rings for boost.

 

[iamdub]

I still see evidence.

Pressure relief valve

 

[iamdub]

Does doing this f~up your cat's or sensors? Piss the neighbors off?

I'm not sure. I wanna say probably not since GM outlines a soak in their oil consumption TSB. But, GM is also the aśśhole that says burning one quart of oil every 2,000 miles is within spec.

I doubt it'll hurt anything. There's no way the combustion chambers and/or rings hold enough carbon to do any real damage to the cats. I don't know how much it smokes. If you're thinking of Seafoam, the good/right stuff to perform the soak contains a lot more active ingredients that burn off in the dissolved carbon. The majority of Seafoam is pale oil, so that's mostly what's smoking when burning. It's not "all the carbon" in your engine. A brand new, carbonless engine will smoke like crazy when Seafoamed.

 

[iamdub]

Does anyone know the factory underhead length for the rear wheel studs? I’m finding between 2.281” and 2.575”. I’d guess it’s the shorter one. I can pull the wheel and rotor off to check but if someone knows or has one laying around... been crazy sick lately and won’t be able to mess with it for a while

No idea. But, to add yet another factor, could it be that the shorter length you're finding is just the threaded portion and the longer is the whole shank, including the unthreaded portion on the end of the stud? That's a difference of .294". I always estimated that unthreaded part to be about .375".

 

[gooffeyguy]

Does doing this f~up your cat's or sensors? Piss the neighbors off?

If your vehicle is Flexfuel, run a tank of E85. That stuff is great at cleaning out the combustion chambers

 

[Geotrash]

Does anyone know the factory underhead length for the rear wheel studs? I’m finding between 2.281” and 2.575”. I’d guess it’s the shorter one. I can pull the wheel and rotor off to check but if someone knows or has one laying around... been crazy sick lately and won’t be able to mess with it for a while

2.281" for the rear, and 2.575" for the front.

More Information for DORMAN 610434

www.rockauto.com

 

[swathdiver]

2.281" for the rear, and 2.575" for the front.

View attachment 367489
View attachment 367488

More Information for DORMAN 610434

www.rockauto.com

I got 2.5" end to end, measured in the dark with my glasses off on that extra axle sitting on my work bench. Measurement includes the head.