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

[Rocket Man]

Well, finally got around to tearing the motor down. Let's just say things do not look good. Both valve covers are coated in milkshake (Coolant mixed in oil) and noted that the #2 Cylinder has coolant on top intake valve. Unsure at this point if it is just a blown head gasket or if I cracked a head/block somehow. Truck never overheated, just started to run rough and blow white smoke on the way home from work. Luckily only drove it about a 1/4 of a mile to get home and shut it down in my driveway, hasn't been fired up since.

The valley also had coolant pooled towards the rear of the block and on top of the passenger cylinder (pooled on top of the head bolts).

Now the frustration begins in looking for the cause and determining if I have to replace the whole damn engine at only 114K miles

View attachment 239426 View attachment 239427 View attachment 239428

Sucks

 

[trailblazer]

How would he know if it’s a cracked block? Replace the heads with new gaskets and roll the dice? Since he’s torn down, is there any way to see?


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[iamdub]

How would he know if it’s a cracked block? Replace the heads with new gaskets and roll the dice? Since he’s torn down, is there any way to see?


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Definitely not something to "roll the dice" on! I doubt it's a cracked block being where he's finding coolant. But it's not impossible if it's cracked badly enough that the head gasket leaks coolant everywhere. That would easily be visible once the heads are off. He's right on the verge of finding out. Just gotta zip out them 15 or 30 bolts. I'm leaning more towards a blown head gasket. I'd still have the heads checked and maybe have a cleaning pass done on the surface to ensure flatness. It'd be ideal to at least check the decks for flatness as well.

 

[89Suburban]

My battery is starting to take a shit, it's only 2 years old.


And when I was under there checking things out I saw this too.

 

[Rocket Man]

My battery is starting to take a shit, it's only 2 years old.


And when I was under there checking things out I saw this too.





View attachment 239467

Looks like a pretty small leak imo.

 

[89Suburban]

Looks like a pretty small leak imo.

Yeah you think I will be okay for a while?

 

[avalonandl]

You should be ok, keep an eye on it. But a new master cylinder is in your future.

 

[Doubeleive]

looks like fun

 

[89Suburban]

looks like fun

It's an expensive little bastard aint it?!!

Pep Boys $135(On sale at 25% off normally $174.99)
Autozone $217.99 HOLY FAK

 

[07Burb]

It's an expensive little bastard aint it?!!

Pep Boys $135(On sale at 25% off normally $174.99)
Autozone $217.99 HOLY FAK

have you checked Rock Auto?