Freeing a stuck engine

Before you get out the sledge hammer and the block of wood and start pounding away, there are a few things to consider. Most importantly:

*What condition was the engine left in when last turned over?

Start by removing the air cleaner. While removing the air cleaner, check for moisture or water puddles in the oil bath. The reason that you are looking for moisture is to determine how much water could be within the engine. If snow has blown into the engine compartment, it will melt and puddle out inside the air cleaner, intake manifold, lifter valley, etc, but not necessarily make its way deep into the engine. If the engine has been flooded by means of overland flooding and rising water, then you could also have an accumulation of silt and dirt within the engine. Dirt and water within the engine is the worst kind of engine lock that you can experience.

Pull the dipstick and check for water in the engine oil. If you find water in the oil, try and determine how much there is. Wipe off the dipstick, attach a pool tester strip to the stick with masking tape and carefully dip the stick in. Note: Pool tester strips can usually be found at pool and spa outlets for about a dollar for 50 strips. The different colored bands will help you to measure how much water is in the oil pan, and if it's clean or dirty.

Open the radiator cap and check for coolant. If no coolant is present in the upper tank, open the drain tap and check for the presence of antifreeze. You can remove a upper radiator hose housing and check under the thermostat too. In some cases, you can open at engine block tap or remove a water jacket stud to look for coolant too.

If the water is from an external source such as rain, and it came into the air cleaner via the butterfly stud on the air cleaner, chances are there is only a small quantity in only a few of the engine bores. You can only have so many intake valves open at one time, and the water would have only migrated into those cylinder bores. Therefore, you could only have two or three stuck pistons at best, and not all eight. In such a case, the likelihood of freeing the engine is much better. On the other hand, if the engine had been flooded by rising flood waters, there is a chance that besides intake valves being open, the exhaust valves open  too. To make matters worse, water also entered in the oil breather and is present in the oil pan. Flood waters also have a large presence of clay particles (or silt), chemicals of unknown nature, and varying acidity and alkilinity.

===Flood water damage===

The clay or silt particles present in flood water will puddle out deep inside of the engine and hang on to the rough casting surfaces of all the internal workings. These clay particles are so minute, that when they are in solution they will infiltrate a bearing. When the water dries, they will form a layer of dust within the bearing. The dust will wick up the oil from the surface and water vapor from the air will start to rust the steel surface over time. The dust will also have acids and alkalines (caustics) attached to it, and together with water vapor will etch the bearing surfaces.

After a flood, priorities arise. Newer, essential and operational vehicles take priority, others will have to wait. The flooded engines will just have to wait, sometimes after freeze-up, sometimes even longer. Internal damage and cracked blocks and heads are usually the result of frozen water. Sometimes they will end up being junked for the cast iron.

==Understanding and preparation==

What you discovered above will lead you to understanding the solution to unsticking the engine. An engine that was in a covered shed, had no visible sign of water infiltration, and was full of oil and coolant but stuck, is usually an easy fix. The rings which are cast iron are stuck to the cast cylinder walls but only in the cylinders which are open to the atmosphere. If you followed the firing order of the engine, you could determine which are open cylinders and which are closed. You can start by pulling the spark plugs out to relieve any compression in the cylinders. Put some diesel fuel into each cylinder with a trigger type oil can. Use a least an ounce in each hole and allow to sit for a few hours. While that's working, back off on the fan belts, remove the air cleaner and valve covers. Charge up the battery, clean the cables and make sure all electrical connections are tight. Remove the fan shroud if there is one. Get a 3 foot breaker bar with a 3/4" drive and the appropriate socket for the front pulley bolt. Remove the coil wire from the distributor/coil. Find two friends and explain what you are about to do and what each one has to look for or do.

With the spark plugs out of the engine and a FULLY charged battery, give the starter a one second click and then stop. Observe as you do this if the fan or crank pulley has moved slightly and which way it moved, if the valves have moved, and if the starter is fully engaging into the flywheel. Take the breaker bar and turn the crank pulley back a nudge and then hit the starter button again to put some torque on the flywheel. This torque multiplication will move the crank journal a degree or two and will push or pull on the piston which in turn will apply thrust against the rings. All you have to do for the moment is crack the rings loose a thousandth of an inch to allow the diesel fuel to get in to that cavity. After allowing the diesel to settle in for a few minutes, use the breaker bar to remove the tension on the ring. The diesel fuel between the ring and the wall will act as a fulcrum and break the ring free from the cylinder wall. It may take a dozen or so tries before all of the stuck rings and bearing are free but with each successive try more fluid will fill the voids until the engine is free to turn. Allow the engine to make two or three revolutions before stopping the exercise. This will allow the excess diesel fuel to evacuate itself from the combustion chambers and for some of the oil in the crankcase to move in the system. The engine will now have a new place to rest while the lubrication seeps into the surfaces of the internals.

Now that you have broken the engine loose, one of the first things to do is change the oil. This will get rid of most of the dirt, acids, and excess diesel fuel. Pull the plug, remove the filter and let it drain for a day or two. Then, add a gallon or so of diesel fuel and a new filter, and turn it over with the starter for a minute or so. You'll be turning it over without spark plugs, so watch for spray coming out of the plug holes. It will turn much faster and build up some oil pressure while cleaning out the oil galleys and internals. You can cycle through a few times if you want.

You now have to make a choice: run the engine as is, or pull the heads and pan to check for damages. If you're going to do a compression test or a leakdown test, drain and re-fill with new oil and start the engine to warm it up and burn off some of the diesel fuel in the engine. In most cases you should go the overhaul route, checking for wear, mic'ing out the bores and clearances of bearings, etc.

==Unsticking the impossible==

The basics of unsticking any engine are the same. Fill it up with a fluid that will penetrate and lubricate any surface. Remove or loosen any accessory or engine part that is not relative to making the engine turn or cause stress. ROCK THE ENGINE, a degree of turning or a thousandths of an inch is a start in moving the engine's reciprocating mass. Allow for TIME and don't get impatient.

Finding a fluid that will penetrate and lubricate is the key. You need something that will creep, stay wet, and wick its way up into the most awkward and obtrusive spot. Ordinary motor oil will coat but creeps at a very slow pace. Petroleum or mineral spirits will get into small places but will dry out over time. Paraffin will wick its way up or down a threaded bolt when it is at the correct temperature. Acids will 'burn' their way and may be hard to control. Caustics are more of a slow burn and will require an outside energy source to work better. Water will penetrate, wet and coat but has limitations. Diesel fuel, is a middle-of-the-road fluid that will creep, coat and stay wet over time. If you're feeling adventurous, you can mix up your own solution (WD40 did).

Know what metal that you are working with and apply the correct solution to get the best result. We know that steel or iron will rust, but how do we penetrate that rust? Aluminum will form a white powdery residue and turn a dark grey almost black coating, what is that? Brass and copper will be covered with a green cakey substance, how do we remove that? Most metals will form what is known as an oxide, where oxygen from the air mixes on the surface with the base metal. We do know that when these oxides dry out they are usually hard to wet and to remove.

Why not just re-wet the piece of metal with the same thing that caused it to fail! If water cause a piece of steel to rust, why not use water to re-wet it and remove the rust; i.e. waterjet.  

Heat is an excellent tool for unsticking things, when used in moderation is the kicker on that line of thinking. If you heated up water to 180 to 200 degrees and poured it in a engine block, what would happen? Would the block expand? If you used a large rosebud flame torch and applied it to the cast iron block, what would happen? Probably crack, most would say. If you applied both hot water and the torch to the same motor block with moderation, what would be the result? What would stay hotter longer water or oil?

Would hitting a stuck piston help it to move? The answer is, yes and no. If you apply enough force in the proper direction, yes it would help. If you just wound up and smacked it dead center with a ball peen hammer, you would probably just put a hole in it and it would still remain stuck. The better way to approach this when you have a stuck engine would be this way:

==Unsticking an Engine in a Manual Transmission Vehicle==