Thread: freeing a stuck motor, best way to do it??????

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i just bought a 67 gto with the original 400 motor, but the sparkplugs were out of it, the owner said that they had been out only 6 weeks, but i am guessing longer, because the pistons are stuck in the cylinders by rust. i gently tried to see if i could break it loose, but it didn't budge, so sprayed some wd40 into the sparkplug hole and am letting it sit . i have heard of many things to spray or pour in the motor to bust the pistons loose. but thought i would ask here, i really don't want to tear the motor apart if i can help it. so what can i pour or spray into the sparkplug hole to free the pistons up.???or only other things i can do?

Dexron sometimes works.

Sea Foam sometimes works.

Engine teardown always works.

And after all that fails there's always the piece of wood the same diamater as you pistons and a gentle rap with a hammer to free the pistons, and I mean gentle.

Old mid-western farmers trick for tractors was to pour diesel or brake fluid in the cylinders and let it sit in ther for a couple days. Put it in gear a gently rock it back and forth. Never done it myself so I am not advocating it. If it were up to me I think I'd go for the teardown/rebuild. After all it was parked for a reason right?

Yea I have no idea why it was parked or why the plugs were pulled BUT if the engine is STUCK then there probably won't be much compresion if you get it to turn. The rings are likley to be stuck in the pistons. Time for a tear down if you expect to drive it anywhere and get back

it was parked because he was 73 years old ,and wanted a small newer car to drive. it had been a dailly driver when he parked it, 5 years ago, I have known the man all my life, my guess is that he went to change the plugs and never got back to it. I know that is was a sound running engine when he parked it in his garage. the car has been about 5 miles down the road from my house, been bothering him for the car for ten years, finally decided to sell it to me.

I'd try PB blaster in the cylinders. that's what we do in motorcycle engines. After you get it freed, check compression and then run 'er until you need to rebuild it.

edit: You do have to let it soak in for awhile (perhaps more than a day) but you should be able to get 'er unstuck.

i've hade this happen to me on acouple of motors and the way that i did it was to mix 50\50 brake fluid and trans fluid,put it in all the cyl's and every day go out with a breaker bar w\ socket and try to move the engine back and forth, and don't be afraid to put a little ass into it and with any luck you should be able to move it with-in the week. if you do get it to move? then turn the engine over by hand about 12 times and then start the engine good luck

Originally Posted by hottrodd57

i just bought a 67 gto with the original 400 motor, but the sparkplugs were out of it, the owner said that they had been out only 6 weeks, but i am guessing longer, because the pistons are stuck in the cylinders by rust. i gently tried to see if i could break it loose, but it didn't budge, so sprayed some wd40 into the sparkplug hole and am letting it sit . i have heard of many things to spray or pour in the motor to bust the pistons loose. but thought i would ask here, i really don't want to tear the motor apart if i can help it. so what can i pour or spray into the sparkplug hole to free the pistons up.???or only other things i can do?

I would pull the whole engine out.If it has been sitting to long you will never get the rust out of the bores.

The diesil method is probably the best way to break loose a frozen engine, What we used instead of a breaker bar was flat round plate with holes drilled in it to go into the pulley bolt holes. Then to that was welded a 5 foot piece of steel bar. Drop the pulley off bolt the tool to the balancer using all the bolts. Torque them down tight, then just slowly rock the bar back and forth untill you get a few full revolutions in. Then you should be able to turn it over with a normal breaker bar and socket.

Give the cylinders a good blow out with an airline. Spin the motor over with the starter motor with the plugs out, also at this time it is a good idea to check oil pressure. Maybe change your oil.

Heres 1 of my tricks, I dont know if you can get BRASSO over there, but it is a liquid metal polish. Once your engine is running air cleaner off, bring your revs up to 2000 or so, and just dribble and I do mean DRIBBLE about 5 CC's of metal polish at a time into the engine through the carb throat. DO NOT POUR IT IN, or you will get a BIG surprise and an engine rebuild for sure.
After you have used about 60 cc's thats 12 dribbles. let the engine on fast idle 800 to 1000 rpm for 15 minutes. Dont walfk away just stand there and listen to it, it should be smooth. Pour in some engine oil flush, let it run shut it down when ready and drain refill oil. That should fix it.

I've freed a chrysler 3.3 v6 up with brake fluid but it smoked and knocked something fierce afterwards. Tore up the rings and lord knows what else. But if your just looking for something to take into a field or around the yard that would be the way I recommend.