Depends on how bad the crack is, and where. Maybe the engine needs to come out and welding being done - expensive. If it's only a case of the water and oil getting mixed then consider using oil in the cooling system.
It would depend on where and why it cracked and it may not be repairable or worth repairing. You may want to consider locating a good used block or purchasing a reconditioned short block.
Repairing this almost always fails, buying a new or used block would be a much better way to go.
Usually oil in the radiator or water in the oil indicates that you have a blown head gasket or a cracked head or engine block allowing oil to seep into the water jackest in the engine. Hope for a blown head gasket...it is much cheaper to repair.
I hate to break the bad news, but if a cylinder is cracked you have two choices: junk the engine or junk the car. Once the block is cracked there is no way to repair it since it is cast in one piece. I've heard of pressing an iron sleeve into the damaged cylinder, but I don't hear of shops doing that any more.
££££ big money mate, have a shop around your local breakers or e-bay for an engine
If it is white smoke, it could be leaking coolant into combustion chamber by a leaking head gasket, cracked block, or warped or cracked cylinder head. If it is black smoke, the engine is running to rich. (too much fuel going into engine). If it is blue smoke, engine is burning oil,(valve seals or rings).
Anywhere between 1000-2000, just replace the engine..too much damage has already been done
it would be better to buy a piston kit. It wouldn't be a good idea to try to fix a cracked piston.
Sometimes. It depends on how large the crack is. There are much better sealers than liquid glass. Glass isn't used much any more and can be very hard to find. If you choose this type of "TEMPORARY" repair I would get one labeled "Block Sealer" as they seem to work best.
No you still have to pay but just not as much
If the engine is not ran much, it could be from condensation build up, or may have been in deep water. If water contains anti-freeze then would suspect a bad head gasket, cracked head or bad block. The heat build up in the oil from running the engine evaporates water from the oil. I would suggest changing oil more frequently until the cause can be verified.
Depends on who performs the repair. Also depends on if the head is cracked or warped. Get estimates from trusted shops.