Car physically can't crank fully

[raptoranderson]

My 1.0 K12 overheated whilst driving and began to lose power sporadically, driving fine one second and then slowing to a near complete stop the next before driving fine again and then stopping. After a few days, I have jumped the car and tried to start it and the crankshaft turns 90* (or there abouts) before stopping. The car physically CAN'T crank. It's like the crankshaft wants to turn but either its stuck on something or the pistons can't be moved any further. My fearful hypothesis is that either the entire engine has seized and the crankshaft has fused to the engine block, meaning that the starter motor is physically moving the entire car body foward an inch or two in an attempt to turn a crank that is now a solid part of the engine or that the combustion chambers have warped around the pistons and the pistons can't push through the chamber.

When starting, the car physically lurches forwards and holds its forward stance until you release the key at which point the car returns back to its original position. No sounds can be heard from inside the engine during start up except the entire car moving forwards, and there are visually no problems with the engine block and nothing protruding from the engine. The oil level is fine and there are no leaks of any kind. The mechanic who towed the car back to my house had a guess and said he thought the head gasket was blown, but surely the engine would still crank. Is this a seized engine?

 

[drand]

if there's water pooled in the cylinders then it won't turn. You're gonna have to crack it open either way really.

 

[raptoranderson]

True, because you cant compress water ... good call. Id rather have it be water in the engine block than a warped or seized engine, depending on how the water got into the combustion chambers in the first place ... a cracked block would not be a happy discovery