I've got an engine that's been sitting up for about 10 years. It's frozen solid. It was running fine when it was ..."stored" (tarp over it sitting outside) but now the pistons are frozen to the cylinder walls.

What's the best stuff to put down in the cylinders to eat through the rust holding them in place?

 

In my opinion, there is no way I would start that puppy or even try to spin it over. Even if you are able to free it up and start it, you're going to bust a ring or something. It may also have rusted valves which will tear up the guides. It will smoke. If it's an original engine that you care about, I'd give it a second thought.

Again, that's just my opinion. I would pull it and tear it down and rebuild it/clean it up. It may cost you less in the long run. With an engine hoist (rented or borrowed/loaned) and a friend, you can have the engine out in a couple of hours. A rebuild would probably be under 2k.

 

In my opinion the motor is probably totatly screwed,,no offense to you my friend. However if it were mine I think I would get a few cans of liquid wrench and spray a good dose down each cylinder ,, through the spark plug holes,,, I would do this once a day for about a week,, then try to turn the motor by hand. If it finally breaks lose,, I would still continue the treatment to try and loosen as much rust as possible by the daily Liquid wrench dosage and turning the motor by hand allowing the pistons to work up and down and help loosen rust. I would then change the oil and prime the oil pump and try to start it. The bad thing is if there is a lot of rust still in it,, it will probably trash the rings and there could be bearings and other things totally rusted too,,, you will end up with a rebuild anyway,, which most likely is your best bet to begin with.

 

What's the worst that can happen - if somethings breaks you have to re-build it anyway. I woulnd't use the liquid wrench stuff though. I would go with Marvel Mystery Oil which would add lubrication. Try the methods suggested - squirting some in each cylinder, change the oil and add about 2 qts Marvel (substituting that for 2 qts of the oil). Get an oil pump primer to try to circulate the oil. Try to turn the engine over by hand (never try cranking it with the starter). If after a while it seems to free up, change all the fluids and try to fire it up. Its worth a try as sometimes it is only one cylinder that is stuck, while it might not be perfect, it still might run ok for awhile until a rebuild is needed.

 

What I'm looking for right now is just something to break the thing loose with. It's frozen solid. I keep hearing there's some stuff out there that will eat through the rust and break it loose. Haven't tried liquid wrench or MMO though. Both of them can't hurt.

 

The MMO (and possible others) will work, but patience is needed, you can't just put some in and then try to turn it over. Put some in, let it sit for a day, try and turn. If not, put some more in if it has drained out, come back the next day, the next, the next, etc. until it frees up. One maybe quicker solution would be to take the heads off to possibly see which cyl is causing the problem and concentrate on that one. At least that way you can see how bad the situation is

 

Had a similar situation a few months back.
Put the engine on an engine stand, removed the heads & turned it until the deck surface was flat (horizonal). I then poured about a 1/4" of PB blaster on top of each piston (4), waited a few days. Kept doing this with both banks until the PB ran down the sides of the pistons. After that happened I poured about a 1/4" of thin motor oil on top of each piston for lube. After a few weeks of that it started to VERY gradually loosen up & I was able to turn the crank enough to remove the piston/rods. HTH, P.S. Don't be in a hurry, it may take some time.
Bob L.

 

Depends if its full of water or not. If you've got some time, Diesel fuel is very good to let sit in the cyls. Other penetrating oils also work well. I just did this with a low mile 305 that has been sitting for 5 or more years. Just let it sit for a week or so. Once in a while go out and try and turn it with a wrench on the crank bolt. The 305 runs great now.

 

My buddy bought a Datusun 240Z, frozen solid. Sprayed a penetrating oil down the cylinders (can't remember what kind but it might have even been WD40) took about two weeks but was finally able to turn over by hand and now has many many trouble free miles on motor. Of course I then had to disown him for buying a Datsun.

 

The little Z cars were pretty good cars. I traded my 71 LS5 in on new a 76 280Z. Only thing wrong with that car was that first wife got it in the divorce!!

 

I have used the liquid wrench and it EATS Rust. I have seen it work, It won't hurt anything but I think I would follow up with some MMO or something , in combination or following this thing being broken loose. At this point,, you have nothing to lose and everything to gain.

 

Yeah I was just kidding he's still my friend and it is a neat car. The color combination floors me it is mettalic pee green with pumpkin orange interior all original of course, I love it. It just screams retro.

 

Sorry bro, but after 10 years outside it's toast. It is certainly rebuildable but not startable. I had an engine that sat outside for only three years and even though I did finally get it to turn over by hand the valves were rusted to the heads. After pulling it apart I found also that the rings were so rusted that there is no way they would have sealed.

 

when i was 16 my 1st car hadn't run in years. got it for free. my buddy towed me at 60 mph in 1st gear didn't start, but it sure was fun

 

Problem is probably rusty piston rings and rusty pistons stuck to rusty cylinder walls. You should open the engine up and rebuild it. Especially where it's now out of the car. But you don't want to do that. You won't know if the technique that follows will work until you start the engine. In order to start the engine, you've got to install it in a car.

1. Do not use the starter. If the engine won't turn, the starter gear can't disengage. Same as a dead short. Very nasty.

2. Squirt some lubricant you like down through the spark plug holes into the cylinders. I've used Marvel Mystery Oil (MMO). You need to let it sit and work its way into and beyond the rings.

3. Turn the engine by hand to work the lubricant up and down the cylinder walls. You can do that at either end of the engine - on the flywheel or the harmonic balancer.

The harmonic balancer bolt won't take much torque. You can buy adapters that bolt onto the harmonic balancer that allow you to get a wrench or breaker bar on them and turn the engine that way. I've used a tire iron leveraging on the flywheel starter ring gear teeth and the bell housing. Ruined the bell housing, but I didn't care about that because I was replacing it anyway. I was careful with the ring gear teeth though because I didn't want to replace that part.

However you leverage the crankshaft, work it back and forth. 20 years ago I freed up the engine that's in my car today. Put lots of MMO in the spark plug holes. Went out to and under the car every day for about 2 months. At first, I was only able to move the flywheel fractions of an inch. But every day was more and more. After about 2 months of this, it went through a complete revolution. I also used a device that spins the oil pump to circulate oil throughout the engine. Spun the oil pump and the engine by hand a lot before I used the starter. Smoked a lot before it started, but it's run fine ever since.

 

Quote
What's the worst that can happen - if somethings breaks you have to re-build it anyway.


I would not recommend that, if a valve drops, or a ring or rod breaks it can destroy the block and heads.

Mark

 

M.Y.Freak has the right idea. Listen to him.

 

While you might be able to get it to turn over using the methods suggested but, as mentioned, it will take a lot of time and luck. Even if you succeed, it will probably still need a complete rebuild (if your rings are rusted to the cyl walls chances are good that other components (like everything that needs to move) are rusted or corroded also. IMO, the time spent trying to get it unstuck would be better spent rebuilding it, which it's likely to need anyway.

 

Outside storage is a death sentence for an engine or car, and covering them with a waterproof tarp can be even worse since it will trap moisture. Inside storage can often be indefinite without significant damage as long as there are not regular episodes of condensation.

If the engine is frozen, it will never seal even if you get it unstuck and running. Your best bet is to disassemble it before more damage is done to maximize what can be salvaged.

Duke