will a block crack of frozen?

.... will a block crack if it just has water in it and it freezes? Wont the frost plugs blowout before that ever happens?... the reason i am asking is i have a coworker that drove 2 hours to look at a Comanche that apparently just needed a new rad. he put a new rad in and the fluid poured out of the block somewhere. he was too lazy to actually look for where the fluid was coming from so he just took his rad out and went home. I was thinking it would more likely be a plug or something vs a cracked block i always thought these things didn't crack that easy. so anyways im thinking of seeing if the lady wants to get rid of it cheap and then drive it to work everyday to drive the kid crazy

Freeze plugs are not really freeze plugs. They are core plugs that are put in to allow removal of the sand that the water jacket mold cores are made of. This is just for the manufacturing process. They are not designed around freezing protection and will not prevent freeze damage at all. I have personally never seen a frozen cracked block, but I have no doubt it can happen. Especially in BC.

I agree with Winterbeater, but take a good light and an inspection mirror and have a look,
you never know.

I had an engine freeze on me, a 140 ford I6, no antifreeze, just water, it did expand the freeze plugs out and I had to replace two of them AFTER leaving it in a heated garage for 2 days for all the ice to melt. Go look at it, you might get lucky.

the renix 4.0 I picked up had a rusted out freeze plug. I pounded it out and put a block heater in it's place. You have to take at least the intake manifold and possibly the header off to get at some of them though. In my case it was a 2" plug on the drivers side rear of the block.

You are taking a chance - it could be a simple freeze plug, pushed out or rusted through. Or, it did freeze up badly, and more than that could be wrong. Cracked head, blown head gasket, cracked block, or maybe a heater valve cracked and that's all.

You won't know until you tear into it and drive it for awhile. Unlike the Ford 300-6, the Jeep 4.0 seems to be a bit more resistant. A Ford would push an internal head plug and constantly overheat until repaired.