Yeah, #5 is the issue. You need to have the head pressure tested and the block. Your gaskets do not look bad. #5 has no water passages from block to head, so most likely is a crack. Here's hoping its in the head!

 

Double fudge.
I'm guessing that means pulling the block!?
Would I be better off just getting a new short block if its not the heads? I don't want to sink mony in the block if it's not fixable...wich I'm guessing bc it's aluminum it's not
The guy at the machine shop suggests turning the crank till 5 is at the bottom of the stroke to see if the lining is in good shape all the way down.
If it's a cracked sleeve ... Is that fixable?

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If you can't find a crack in the head I would not mess with the block, too many ways to screw that up. Much easier to just get another engine and start from there. Lots of rust buckets with low mileage for sale in the upper midwest and northeast, perfect donor cars. Good luck.

 

If it's not in the heads, I think I'll just go w/ a top hat style short block from AB or others.
​​​​​​I should hear back about the heads by next week. I'd rather replace the head than the block, but the machinists said he had only rarely seen cracked heads on the Buick ... Still here's hoping!

 

Bad news confirmed, The machinists said both heads pressure tested good.
Looks like I'm up the creek.
Last bit of advice if I may:
Im inclined to get a new short block so that I dont have to tear it all down again in a few yrs for rings, or mains or seals etc.
If I go with a new short block, guessing I should get a new front cover and oil pump while I'm at it yes?
Thanks!

 

 

I love this truck. I'm no off roader, but I can manage just about any repair on it myself with wrenches and an OBDII. the interior is still in great shape(thx to the new headliner I installed ) truth... I would love an x5, but I'd also love to not have a car payment again for a while.
This is my vehicle, and the family excursion vehicle and I travel a lot. I'd like to enjoy it again for a while and not have to F with it every time I'm home.
I considered a low mile engine... But it seems kinda risky to me. As far as I know the gaskets are already half cooked
​​​​​​I feel like with a new short block, I'll know the state of the engine is solid... Also will be adding analog sensors for oil pressure, temp if nothing else... Maybe I'll wire it to an arduino to give an audible alert when the temps reach 120
Maybe its not the most reliable vehicle by reputation, butFor a 16 year old truck I never had an issue with it till last year.

 

 

For the time work and money you're gonna put into another engine you could buy 2 or 3 trucks you need to think about this bigly

 

Actually, if it were me, I'd put head gaskets in it and try it again before I do anything.

your vertical gasket pics, can you post a close up of that area? The second pic has a hole in the middle that looks wonky.