Hey Guys,

I have a question. Does anyone know if it is possible to manually turn over an engine while the spark plugs are still inside?

My dad's car died, and the mechanics concluded that the engine seized because they manually tried to turn it over and couldn't. However, they never removed the spark plugs. So i am thinking maybe the spark plugs needed to be removed?

Thanks.

 

You can, but if the valves and their seats aren't severely contaminated and the compression rings are still working well, it's not going to be easy. And can be dangerous as in broken wrists or arms.

One way to try to turn the engine at least a little without removing the plugs is to do this (requires the transmission to be a manual). Put the transmission in fifth or sixth gear, release the emergency brake, and try to rock the car while someone is watching the surpentine belt and pulleys. If they move, then the engine is most likely not seized.

 

Yeah, this car was an automatic, 98 ford windstar, it had about 105k miles. I think they put it in neutral and tried to turn it via the crankshaft. It would go about 1/4 turn and then stop. And i think they applied a moderate amount of pressure.

 

Yes its possible. Its hard but possible.