How To Unseize Your Classic Car’s Engine

Author: Jason / Date: August 9, 2022 / Tags: classic cars

(RareCarMarket.com) – An engine typically seizes when there isn’t enough oil to properly lubricate all the necessary parts, resulting in friction and heat, which can fuse moving parts. Yet sometimes intricate moving parts simply sit idle too long and freeze in place. Most people assume they need a new one if this happens, but that’s not always the case. It is possible to unseize an engine — it all depends on how much time and effort you’re willing to put into the project. 

The first step is the easiest. Try to spin the engine manually using a socket and breaker bar on the crankshaft. 

If your muscles aren’t enough to move it, fill the crankcase and each cylinder with penetrating oil or diesel fuel and let it sit for a day or two. Try to crank the engine again manually. 

If it still won’t budge, it’s time for some serious work to begin. You’ll need to disassemble the engine block completely, cleaning and manually checking after each step. Start with removing the valve covers and rocker assemblies to check for a stuck valve. Next, move on to the actual intake and, finally, the cylinder heads. 

The video below shows them heating the engine block with an acetylene torch, but that’s only for extreme cases and best left to professionals.

If you still can’t manually turn over the crankshaft, you have bigger issues to worry about, which could lead to a discussion of whether the engine is worth fixing or not.

Of course, an ounce of prevention is the best cure and the best advice to avoid these scenarios. Always make sure there’s enough clean oil to lubricate the necessary parts in your car. 

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