Cracked Block From Old Head Bolts?

[Smuggli]

I am wondering if re-inserting the old head blocs after they were removed could have caused a crack in the block. New the forum and the A4, but I honestly think my mechanic cracked my block. They wanted to remove the old bolts before putting on a new head because they were bent. Ended up with three new bolts and they just put the old ones back in. They said no crack in block before this work, then they "found" it after this work.

Before


After


Am I crazy or did these guys crack my block?

[Mo]

Looks like someone had applied heat to loosen stud...heat and cast iron don't always fare well. Your suspicion may be well founded. Hitting the stud to try and loosen it could also do that. That said, it's also not uncommon for a crack to appear between the cooling passage and the stud. Might be able to fix it with JB Weld and it could run for years without issue. Personally, I'd keep the T-stat out of the engine if you put it back together...overheating issues can lead to all sorts of "unforseen" problems. A few members have fixed issues such as you have there with JB Weld and I wait and see what people have to say before throwing in the towel.

[lat 64]

I think the bent head bolts(studs) are the clue here.

At first I thought this was a freeze crack, but I'm not so sure now.
The crack looks fresh to me. I see bare, not-rusted metal down in the cracks nearest the stud.
How did the studs get bent? The force that bent them may have cracked the block.

[hanleyclifford]

It's a bad idea to apply heat to get a head stud out. The stud expands faster than the casting and that can be trouble. The crack could also have been caused by excessive torque being applied to turn the stud out. There is no substitute for patience and Kroil or PB Blaster. Still, I would make an attempt to repair with JB Weld.