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

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89Suburban

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Using the tire chalk trick for final pressure adjustments.


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Doug118

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Never in my life have I seen a stock vehicle have a piston melted this bad. 2 others had part of the top ring land missing and the other side of the engine had a broken valve spring. This poor engine had a hard life

Before anyone asks, yes I changed the 4 pistons with the block still in the truck
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swathdiver

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swathdiver

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Meaning a 6.2 that ran on 89 or a 5.3 that should have run 89?
Many people run the 6.2s on 87 or 89 and we've seen on these forums that after about 100K miles of doing that, they start breaking pistons and rings. The cars are so big and well insulated that knocking and pinging can really only be seen with a scan tool in all but the worst situations.
 

intheburbs

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Many people run the 6.2s on 87 or 89 and we've seen on these forums that after about 100K miles of doing that, they start breaking pistons and rings. The cars are so big and well insulated that knocking and pinging can really only be seen with a scan tool in all but the worst situations.

In order for the knock sensors to do their job, there has to be some amount of knock for them to sense, right? Yeah, no thanks.

Even when it was $5 a gallon here in Michigan, we dutifully fed our L9H nothing but 93. I still have to get around to running the tank way down and filling with E85. Just for S&G. Gimme dat 100-octane stuff!
 

RooTBeeRthe1st

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Rolled 180 this morning.

Anybody know of high torque starters for these things?
Thinking of slapping one in when I eventually plop the new engine in, for **** and gigz.
 

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iamdub

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Rolled 180 this morning.

Anybody know of high torque starters for these things?
Thinking of slapping one in when I eventually plop the new engine in, for **** and gigz.

I'm not the authority on this, but I found myself researching starters for these when I ran across a new AC Delco starter for $100. Part number said it was for the Gen 3 engines but I couldn't find any difference. RockAuto showed it to fit the Gen 4 engines as well. I went ahead and scooped it up figuring I could resell it if I couldn't use it. Anyway, it looks like there are 9-tooth and 11-tooth starters that are otherwise identical. Obviously, the 11T has more cranking speed and the 9T has more cranking torque. The new one I got ("for a Gen 3") is a 9T. I *read on the internet* that either work on the same GM flexplates. I manually held it to the LC9 (Gen 4) on the stand it it looks to fit and gears mesh as they should. I'll be swapping it into my Tahoe and will compare it to the existing starter in appearance and measurements.

So, that was a long way to say that, if they are interchangeable, you could get an OEM 9T if you currently have an 11T. Unless you have a need for an aftermarket starter designed specifically for higher torque than even a factory 9T starter has. My LMG has slightly higher compression but the original starter, even at 225K miles, is doing fine. I don't need maximum cranking speed. I'd rather the reduced current draw of a mechanically torquier starter, however minimal.
 

Doubeleive

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Rolled 180 this morning.

Anybody know of high torque starters for these things?
Thinking of slapping one in when I eventually plop the new engine in, for **** and gigz.
I always thought it went by kilowatts, ones available for our vehicles seem to range from 1 to 1.7kw
whenever mine dies i will replace it with a 1.7
the one on my 18 silverado seems weak so I was kind of already poking around
 

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