Diagnostic Resources

Miracle Formula for a Stuck Engine
Edited by Kim Pratt

Another great discussion from the Tractor Talk Discussion Forum.

The discussion started out with the following post:

"I have a stuck 4 cylinder engine. Two pistons right at the top, other two down. From underneath everything looks good. Up top looks bad. Thanks in advance."

What followed are some interesting replies:

" This might sound kind of quirky, but alcohol has a way of working it's way thru anything. I'd try a penatrating solvent first tho'. Alcohol for the equipment not the operator. Dunno if this helps or not, good luck! "


" Would you not be worried that alcohol consists of mostly water? I've also heard that coca-cola is good for the same purpose, maybe the water is the secret. It's worth a try to pass this logic pass your wife, when your justifing your purchase of a 1/2 gal. of Old Grandad. Or what if the preacher drops by, "oh, I just use that stuff for rusty bolts and such". "

" Alcohol works well,try it and let us know the outcome. "

" As for the reply suggesting coca-cola, Strongly suggest using the diet variety if you go that way. The active ingredient that acts as a rust cutter is phosphoric acid, same as in Naval Jelley or Rust Mort. At least if you use Diet you won't have the sugar gumming things up. Actually the best tried and true remedy is good ol Marvel Mystery Oil. Rislone works just as well. Need to keep things soaked in the stuff for a few weeks if possible. Then spray in the diet coke or rust mort to dissolve the hard stuff. Good luck, you'll get it loose if you have the patience. "

" I haven't tried this on an engine, (I really like to avoid sticking an engine) but the best general-purpose rust penetrant I've found is Kroil from Kano Labs. See: www.kanolabs.com "

" I have had pretty good luck with Marvel Mystery Oil. "

" Kroil is the best penetrant. The key to "unsticking" a engine is paitence. It takes time for an engine to set up, and it will take time to free it. Don't try to rush it. "

" I have found that Oil of Wintergreen is a wonderful penetrant. I was shown this trick by some old aircraft mechanics and have had alot of success with it. I was able to unstick an antique briggs in a week and didn't even have to tap the piston at all to free it up. Last time I bought it I purchased it at a drugstore. "

" I've been away from the computer for a few days and was catching up on some reading on "Tractor Talk". I was looking at the ideas for unsticking a frozen engine. I had to look at the calendar and make sure it wasn't April 1st. Also thought maybe Martha Stewart was writing in. Do some of those crazy ideas actually work or are y'all jes funnin' me? "

" I came in on this late and I swear Marvel Mystery oil is the way to go. Mix it 1 part to 2 parts kerosene. Dont mean to muddy the water anymore but I had to get my 2 cents in! : ) "

" I use marvel mystery oil alot whenever I am rebuliding an engine but the problem with marvel mystey oil and kerosene is that its too thin. I use 1/3 automatic transmission oil (great solvent try on your hands some time),1/3 marvel mystrey oil, 1/3 kerosene. Leave the plugs out. Put in first gear, as you walk by just lean against a tire once, then the other. Sounds crazy, never broke a piston in about 15 stuck engines "