how to unlock rust-locked cylenders

[chevota]

water got in through the intake valves on the 2nd and 4th pistons...rustlocked. How could I unlock it? Someone told me to pour marvel mystery oil on the pistons and let it sit

[rockcrawlintoy]

that will help, shoot some PB blaster in there also

Drew

[chevota]

tried turning the crankshaft after weeks of soaking with marvel, pb blaster, gas...gear oil, etc. Broke two half inch drives on two different wrenches. Any more suggestions? guess this means bore it out, and get new pistons and rings.

[rockcrawlintoy]

we used a 1 inch impact gun once. thats right a 1 inch drive impact gun

Drew

[tf]

I got a dirt bike with a locked piston for free! It had been stuck for 2 years. When i got it home i took it apart and poured a can of coke on the piston. A can of coke, couple of days, a rubber mallot and a BFH, it eventually broke loose with some love from the BFH. Place the head of the rubber malot on the piston and hit with BFH. It might be worth a try! ;D

Good luck

Trav

[Hoodlum]

My dad's friends restore old cars and have been doing it for over 50 yrs and I've seen this work time and time again but it is a SLOW process they put one ounce of mystery oil per cylinder let sit for a week then put 1/2 oncer per cylinder and then turn the crank by hand only a 1/4 turn then each day they do a 1/4 turn until they get a full revolution then turn it a few times I've seen a car that sat for 35 yrs turn over and run after this process yes this is a very slow way to go but sometimes it's worth it

[chevota]

the pistons are completely locked

they dont move at all....

what is a BFH??

thanks, alex

[rockcrawlintoy]

BFH = Big Freakin Hammer

Drew

[yamaharacerx]

Use automatic transmition fluid. Works every time.

[motivation]

Even if you manage to get the pistons free. i would not feel comfortable running any engine that was locked up due to rusting because the rust is still there. And if it gets into your oil it has the possibility of ruining some bearings and causing even more damage. I would suggest a full rebuild, but go with a minimum tear down and hone the cylinders, remove rust from pistons, get new rings. That may sound like alot of work but small price to pay for reliability. Good Luck

[k20]

you will need to re bore it,that happened to my inboard boat engine,the rings started to eat into the bore!

[kneedownnate]

My ground strap on the back of my head came off and electrolysis got the better of my head. I drove it for nearly a year thinking the head gasket was blown, then parked it in storage for a few months. When I went to retrieve it it wouldn't start, wouldn't even crank over. I checked the battery and it was fine, put two and two together and realized it was rusted solid. I put it in 5th gear and rocked it back and forth as hard as I could till I hear a loud ping, then it moved freely. I parked it again a few days later, siezed the engine in my 4by and needed a donor so I went to retrieve it again and had the same problem. I pulled the head thinking I would have to replace it, when I saw that it looked like the #3 and 4 cylinders had been sandblasted. I said screw it and put on a good head, and drove the 4by for maybe a year or so before the water pump went and warped the head, so I pulled it to slap on a 20r head and the cylinders didn't look too bad. I've put about 30k or so more miles on this setup with no problems, so you might be in luck. Not saying you'll have such luck, but you never know.

[live4yotas]

I have heard of using coke to. It eats rust. I have also heard of filling it full of oil and puting a wrench on it and hanging weights of it and letting it sit till it breaks loose.

[ediblecrayons03]

what about kerosean (sp)