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4.0 siezed?


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anyone know what to do to get my pistons un froze? i put some lube down there and already took off the oil pan and checked everything to make sure it was the pistons and it is... the truck has been sitting 5 years so any suggestions?

 

stop, drop, and......

 

 

 

 

 

 

 

 

 

 

replace.

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Pull the plugs and fill the cylinders with a good rust penetrant. I don't know if PB Blaster comes in a liquid form. Kroil does, but it's expensive and hard to find. Maybe just put the nozzle of a spray can of PB Blaster in each hole and let 'er rip.

 

Repeat spraying in the juice daily for about a week. Then try turning it with a long breaker bar and socket on the nut at the front end of the crankshaft. do NOT try to use the starter motor.

 

If that doesn't work, you'll have to pull the head. Remove the head, repeat the soaking with PB Blaster (or equal, but NOT WD-40) for a couple of days, then get a length of round hardwood rod. Don't get dowel stock, it's too small. You want the stuff Home Depot sells for closet rods and/or stair handrails. You could also use a utility grade 2x3, but that's soft wood and a couple of whacks may trash the wood.

 

Cut the rod to about 12" to 15" long. You're going to put one end of the rod on the EDGE of the pistol, on line with the wrist pin (which means at the front or rear of the piston, not on either side). Push down to make firm contact, then smack it a couple of times with a big hammer. Do the front and rear of one cylinder, then repeat for each cylinder. If one cycle per cylinder doesn't break it loose, soak it some more and repeat the next day.

 

If you do get it broken loose (it can be done), remember that there's a lot of rust in there. If it were mine, what I would do next* is buy, rent or borrow a ridge reamer (to cut the carbon ridge off the top of each cylinder bore) and a cylinder hone. Hone the walls of each cylinder, with the crank and pistons in place. Clean everything out as well as you can. Clean up the valves, install new valve seals (since you have the head off that's easy to do), get a head gasket, and put it all together. The rings will have to reseat -- which they might do, or they might not, in which case you'll always burn a little oil and maybe lose some compression, but it will run.

 

 

* Truth in advertising disclosure: This is what I would do if I were you. If I were me, I would already have the ridge reamer and the cylinder hone, because I have already gone through this exercise.

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  • 2 weeks later...

if it were me and I'm a savage.. I would get a threaded fitting for a grease gun and use hydraulic pressure to punch the piston out..

 

With that theaded fitting for the gun .. you remove the spark plug and start pumping the S%#^ outta it.. while you have a long breaker bar on the crank nut.. turn the breaker bar while filling the cylinder with grease.. it's going to be quite the mess to clean up but it'll get the piston moving.. I've done that quite a few times on Aircraft engines.. and the theroy would directly apply to automotive engines.. but yet again.. Automotive piston engines are much more complicated than aircraft engines.

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With that theaded fitting for the gun .. you remove the spark plug and start pumping the S%#^ outta it.. while you have a long breaker bar on the crank nut.. turn the breaker bar while filling the cylinder with grease.. it's going to be quite the mess to clean up but it'll get the piston moving.. I've done that quite a few times on Aircraft engines.. and the theroy would directly apply to automotive engines.. but yet again.. Automotive piston engines are much more complicated than aircraft engines.

The problem is, with a frozen engine the best you can hope for is that both valves will be closed on maybe two out of six cylinders. On the others, you'll just be pumping grease into the exhaust manifold or the intake manifold.

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