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

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iamdub

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Literally the only issue of noticed, besides the elevated oil consumption, is that either exhaust leak or valve train noise, and the exhaust leak is completely unrelated if that's what it is, and the valve pick, has slowly been getting worse over time and didn't happen until maybe 6 months after it overheated when I noticed, so likely also unrelated.

I'll probably just measure the bore both directions down every cylinder in the top middle and bottom just to check for uniformity and make sure that's not an issue, just trying to save down time when I rip it all apart.

Set aside a whole day for it, and it's boringly monotonous work, but I'd strongly recommend a thorough compression test before you tear it down. Closely document everything you find. Pouring a little oil into each cylinder and testing again would differentiate between rings and/or bore and valve sealing issues. Measuring after you have it torn apart would tell you how much, if any machining you should do.
 

RooTBeeRthe1st

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8mo?
 

RooTBeeRthe1st

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Set aside a whole day for it, and it's boringly monotonous work, but I'd strongly recommend a thorough compression test before you tear it down. Closely document everything you find. Pouring a little oil into each cylinder and testing again would differentiate between rings and/or bore and valve sealing issues. Measuring after you have it torn apart would tell you how much, if any machining you should do.
yeah, i def want to to comp and leakdown before i tear it down.
pretty sure i have pics of previous numbers...cant tell what cyls from pics though.

Another news, ran to home Depot with it to pick up some bug killer because my house plans have a ton of gnats all of the sudden. Ended up picking up lavender plant in the meantime since actually have some right now. Had to put it on the passenger side floor mat because I have so much crap in the backseat and cargo area... I really needed a garage about 10 years ago.
 
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RooTBeeRthe1st

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Finally swapped the white DRL bulbs back out of the turn signals and swapped in amber led bulbs in. Also changed the cabin filter. Wasn't too bad actually.
 

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RooTBeeRthe1st

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And I guess I didn't test it thoroughly enough yesterday when I was installing them. But I definitely have hyper flash now even though the tail lights are still the original bulbs.
 

Doubeleive

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Finally swapped the white DRL bulbs back out of the turn signals and swapped in amber led bulbs in. Also changed the cabin filter. Wasn't too bad actually.
you will need resistors or bulbs with resistors built in, the only seller I have seen with resistors built into the bulbs that actually worked is auxito
you have to get them from this guy though because others are fakes or not work
 

Charlie207

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I’ve been getting an average of 12mpg e85. I changed my tune to 89/91 BBP tune and on the way to the airport I was getting 18mpg, we’ll have to see what the average turns out to be over time but so far I’m a fan. Lol

I've been seeing 18+ MPG highway if I set the CC to 70mph. Some areas are less hilly than others, and I saw sustained 20mpg for an hour.

Also ordered four hub-centric ring spacers for 78.1mm to 112mm, aluminium.
 

RooTBeeRthe1st

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you will need resistors or bulbs with resistors built in, the only seller I have seen with resistors built into the bulbs that actually worked is auxito
you have to get them from this guy though because others are fakes or not work
On my 1980 it was nice and easy, I just got some flasher units that had a knob on them to adjust the speed of the flash when I swapped all the bulbs out for LEDs.
Unfortunately, these newer vehicles aren't so easy.
I don't like resistors, they seem like a Band-Aid rather than a proper fix. I probably still have some left over from my Subaru that I didn't use though.
 

RooTBeeRthe1st

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5?! I thought the spare tire does not have a sensor on these cars.
Mine did when I needed it. Showed up on the dash a couple pounds lower than all my other ones. Meanwhile the one I took off was completely flat.
 

RooTBeeRthe1st

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I've been seeing 18+ MPG highway if I set the CC to 70mph. Some areas are less hilly than others, and I saw sustained 20mpg for an hour.

Also ordered four hub-centric ring spacers for 78.1mm to 112mm, aluminium.
How thick are the spacers?
 

Charlie207

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Rocket Man

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On my 1980 it was nice and easy, I just got some flasher units that had a knob on them to adjust the speed of the flash when I swapped all the bulbs out for LEDs.
Unfortunately, these newer vehicles aren't so easy.
I don't like resistors, they seem like a Band-Aid rather than a proper fix. I probably still have some left over from my Subaru that I didn't use though.
The only other workaround is a BCM flash from BT Dieselworks. You need an Autocal and then he’ll email you the file. His Autosync won’t disable hyper flash for the GMT 900’s. I did the BCM flash on my 08 Silverado.
 
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The only other workaround is a BCM flash from BT Dieselworks. You need an Autocal and then he’ll email you the file. His Autosync won’t disable hyper flash for the GMT 900’s. I did the BCM flash on my 08 Silverado.
The AutoSync has programming mode now, so you don't need an Autocal to flash the BCM. The file is either sent on a microSD card that plugs into the AutoSync or it updates over the air, not sure which exactly.
 

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