Seized engine

[Robert I.]

Trying to get a stuck engine to rotate.

How much torque can I put on the crankshaft bolt?

I can get it to turn, but not the crank.


If Marvel Mystery Oil doesn't work, would it do any good to remove the heads and spray some PB Blaster directly around the pistons?

[Domenic T.]

Re: Seized engine

Bob,
You can remove the plugs and put your favorite penetrating oil thru the spark plug holesthen usa a rubber tipped air nozzle and push it in the plug hole one at a time till you find one or so with compression.

The air pressure should move the piston down.

If that dosen't work then turn it at the flywheel using the teeth with a flywheel turn tool or a LARGE screwdriver.

DOM

[Timothy B.]

Re: Seized engine

Robert,

I agree with Domenic, turn the engine at the flywheel and don't strip the crankshaft screw. Lots of penetrating oil first..

[Dick W.]

Re: Seized engine

Patience! Give the MMO plenty of time to work, maybe a couple of weeks. Go to the flywheel and try to turn it both ways. Keep doing this every few days until it breaks free. I have a rather large engine (586 cu in) that took over two months to free up

[Doug F.]

Re: Seized engine

even if you get it to turn it will still need "work" on at least two cylinders, so the heads have to come off anyway, so other than the satisfaction of getting the engine to turn over, what have you accomplished for all the time you have spent? we have encountered plenty of engines where getting the piston out of a block with no heads or crank, without splitting the wall was a major trick

[William G.]

Re: Seized engine

ROBERT
Purchased a 67 427/390 that had been sitting for 5 plus years amd
was frozen up. I removed the sparkplugs and filled each cyl with
transmission fluid and let set for 4 hours. When i came back it rolled
over and started. Maker sure it is outside because it will fill the
street with smoke.
Good Luck
Bill

[Dick W.]

Re: Seized engine

Do not try to push the car to break the pistons loose. You can end up bending a rod. If the car is a manual transmission, you can put it in 4th gear and try rocking the car back and forth. Too much effort and you can break the ring lands on the pistons