frozen engine....
 

A guy asked me how to unstick a frozen engine. The car has not run in about ten years but, due to being kept inside, looks nice. This is a W110 we are talking about.

I usually just remove the spark plugs and pour an ounce of automatic transmission fluid into each cylinder. Then I let it sit for a week. That usually frees them up.

But is there anything better out there? Just because I have been doing something for the last fifty years is no proof I have been doing it right.

So what have you used to free up an engine?

If it's a W110, it's either a 121 gas or 621 diesel engine. Pop the valve cover and glop oil on the overhead cam lobes which are probably pretty damn dry.


If you want to go crazy on oiling like Chuck Crittenden does, create a oil pumping system that works through the oil pressure gauge sender unit connection. That way, you can oil all the bearing surfaces before starting

Patience, patience and more...put THIN oil in cylinders as you said and all over the camshaft, followers, timing chain, valve stems. Walk away for days and then try turning by hand. If no success put a bar on the crankshaft, tap it lightly and again walk away. Repeat this process.

Being patient and not using a lot of force may prevent serious damage to the motor.

We did the valve cover removal thing. The cam was coated with a sort of oily film that we cleaned off and then poured oil over everything to create a 'clean' seal. The cam and the followers looked better than I thought they would.

A connection through the sending unit is not a bad suggestion but I usually just do an oil change with a filled canister and new filter. Then turning the engine over by hand will eventually get the oil through the system. And since it is done slowly there is no heat build up. This might not be perfect but it always seemed to work.

I have, in the past, put the cheater bar on the crank bolt right from the start. The engine either turns or it stays stuck. Knowing how much pressure is needed to turn over the engine is a big help here.

I normally tap the end of the cheater bar with my open palm to try and snug it loose. This sometimes works, sometimes not. And if not more light oil and time. Then try, try again.

I am considering using Three in One blue top oil since this seems to work well on lubing up electric motors, like blower motors. Someone here suggested this for blower motors and it works great.

I have also been told Marvel Mystery Oil. Isn't this just like using ATF?

50%-50% ATF and acetone.

if its real hard it will not last long,after you break the engine loose.Better to find another motor or rebuild.

Indeed - how stuck is stuck?

Try the ATF or the ATF concoction and if it still doesn't move then I think the kindest thing is to remove the head and the crank and tackle each piston individually.

Kerosine in cylinders

An old trick for frozen engines is to pour a mixture of Marvel Mystery Oil and Coca-Cola (diet) into the cylinders to soak for about one week. This technique is used with the thought that the engine will be rebuilt once dis-assembled. Coke has phosorphic acid. If you decide to turn the crank with a breaker bar turn only about 1/4 turn each day.

Does acetone harm parts such as pistons that may be within service limit specs if it sits/soaks for an extended period? Have heard it is great for breaking rusted bolts loose. Why/how does it work?

When trying to move it with a bar at the crank, lightly tap the bar in both directions.

Kerosene...if you fill the crankcase it would reach the bottom side of the cylinder walls and wrist pins, adding it to the cylinder only gets the top of the cylinder wall that isn't blocked by the piston. It would be one clean engine once drained:)

Keep us posted!!! and Good luck!!!

Acetone never sits for very long. Once it separates from the ATF it evaporates quickly leaving behind the ATF as a penetrant/lubricant. Its main purpose is to thin the ATF and loosen the carbon bonds.

The mixture shouldn't be used as a lubricant.

I may just try one thing and then another and report back on the results.

The owner is thinking rebuild if necessary. Of course it will someday be necessary (this is true for any engine) but they hoped to get some driving out of it first.

A lot of great suggestions. I would have never though of acetone but it makes sense since it seems to cut through just about everything and is cheap.

And just filling the whole thing with kero is also worth trying. Rust is rust and it is not exclusive to the piston rings.

More on this as it develops.

Clean up all the cylinders first so you do not get the crud stuck in the rings. Soak with your solvent of choice. Pry the engine at the flywheel. You will get a lot more rotational force there, than at that front crankshaft bolt.