Well, the worst has come - head gasket or cracked sleeve

[dikidera]

Yeah I would have thought that because this is the 140hp variant, that is, it has been software limited then the engine life would have been extended + it would not have had those power pressures as the 170hp variant and thus a blown head gasket to be more likely than the block.

I would shim it...but the shop said they don't do that...which is unfortunate because why would I fix it in one shop to open in the next and future proof the sleeves. I could try to take the head off myself and fix it myself(well, send it to be checked for straightness and sanded) via VIDA or something, but...if I fail in something most shops do not like and are more likely to send me away if I bring them a car I tried to fix myself and failed. I've had the opportunity to talk to a lot of mechanics who've dealt with people who tried and failed to fix a car and don't like the situation one bit - can even become condescending.

[BlackBart]

"theres an inherent weakness between middle cylinders, more common with R variants."

RRrrrrr

[vtl]

theres an inherent weakness between middle cylinders, more common with R variants.

These slots are for thermal expansion compensation. Without them the sleeves have no easy place to go but lift up the head.

[erikv11]

That makes sense, good to know. Regardless of why they went with the cuts between the bores of the open deck, that's definitely where the larger bore blocks most frequently crack. Inherently weak there.

[dikidera]

theres an inherent weakness between middle cylinders, more common with R variants.

These slots are for thermal expansion compensation. Without them the sleeves have no easy place to go but lift up the head.

This implies shimming is another can of worms, yet people do it consistently and can top 600 bhp or was it whp.

[vtl]

This implies shimming is another can of worms, yet people do it consistently and can top 600 bhp or was it whp.

600 bhp is a low average load, since in most of places on Earth it is illegal to drive long distances at speeds possible with 600 bhp. The problem kicks in when you drive under high load for a long time. For example, XC70 as an overlander, with steel roof basket loaded with gear, a full family inside, 10 hours a day, every day for 2 weeks. Remove the head and you'll see cast iron sleeves punched the head. Add shims, and sleeves will pick up the head to gasket failure.

Shims help fighting a consequence of detonation. If the engine is a work horse, the shims only make its lifespan shorter.

[dikidera]

Define "a long time".

Also detonation as in knock or detonation as a synonym for combustion? I've read that the sleeves can't take past some HP pressures due to boosting(even stock R) and shims help with this OR future proofing your stock engine from cracked sleeves. Sounds like shimming is the better evil - gasket failure vs cracked sleeve.