[AK Viking Owner]

Long story short I got a 2015 Viking at a great deal. I knew I would have to go through everything as it was pretty neglected. Head gasket and the gasket between the cylinder and case were both blown. Got it ripped apart and found out why….At some point someone took the cylinder out and stripped the bolt hole. Any info on going up a size on the bolt? Don’t want to hit any passages or anything.
I tried running the same size tape and cleaning them up with no luck. The helicoil that was installed was wrong and didn’t hold at all.
Appreciate any help thanks!

 

[cactus]

I was going to say to use a helicoil but that's already been done. Can you re-do the helicoil with Thread Locker or is it too far gone? The problem with going up a size is finding a bolt with the same size head and shaft but with a larger thread. And without looking I wouldn't imagine that there would be any oil galleys around that part of the engine.

It's unusual for a base gasket to be "blown", was it leaking oil?

I'd go to an engineering shop or bolt shop, or ring helicoil and see if they have any solutions. Would your dealer be any help?

 

[AK Viking Owner]

No oil leaking, leaked coolant after throwing the new head gasket on and running for a few minutes. I was able to clean it up and run a new coil and it held torque. You were right on the bolt head issue. Figured we could go up to an 12mm but the head wouldn’t fit in the hole.

 

[cactus]

Yeah you'd have to grind down the flared part around the head, then that would cause torque down issues. You might be lucky and find an imperial bolt that was just slightly bigger, maybe 3/8 inch?