17 replies to this topic

[benbarnes]

Hello,
I have recently found out that the engine on my project mini is actually seized!! It has been sitting for a very long while, and it looks as if water has got in to 2 cylinders as they are quite rusty. What is the best and cheapest way for me to un-seized it?? Are the only options to get new pistons and get it re-bored, or to get a second hand block with pistons? Or is there a way to do it on the cheap myself?? Ive tryed soaking it in penetrating fluid over night and it drained through 2 cylinders but not the rusty ones, and i've also tryed heating them up, but they seemed to be fused very tightly!! Please help.... All advice is welcome........

[benb12]

I think diesel down the cylinders is supposed to work wonders... but if you tried penetrating oil I can't see it being much better.

[Big_Adam]

Diesel down the cylinder WALLS and leave to soak overnight.

Next day try turning it over with a braker bar and a socket on the bottom pulley. Be sure to turn it the right way as you want to pump oil from the sump round the engine ... also make sure you have oil in the sump.

Then just try and turn it BY HAND.

If it will not move smoothly after a duration of hand cranking it, then you probably screwed. If after a few turns it seems fine then its just surface rust.

[benbarnes]

i'm worried its more than surface rust but I will try the diesel idea. I soaked it overnight with penetrating fluid but it only flowed through the 2 clearer cylinders not the rusty ones, but it might take a couple of soakings to get through. Would pushing the car in second gear do the same job as turning the crank with a breaker bar?? Or is it best to only do it with a breaker bar?

[Big_Adam]

Oh, if its in the car, stick it in reverse and push it backwards.

Does the same job, don't forget OIL IN SUMP.

[benbarnes]

yeah the engine is in the car still, i've just taken the head off. Ok I will try that and see how it goes, there is new oil in it so thats no problem.

[Cooperman]

If it is seized that badly one might expect that it'll need a re-bore and new pistons, so a omplete re-build is probably on the cards if it is to run properly. What size engine is it?

[Pauly]

Boiling hot oil can work aswell, stick it down the bores and it should trickle through the rings and free them.

[benbarnes]

Ok I will try the boiling hot oil idea as well. I havent had much luck with anything so far. Yeah I was worried it would be an engine rebuild/re-bore etc but if I cant free it up I will propbably just get a cheap second hand block/engine from ebay as they are very cheap. Its a 998cc that is currently in it.

[Guess-Works.com]

It will be VERY difficult to push the car and turn the engine when it's in reverse, the gear is WAY to short to do this...

Think about it, the FD is say 3.4, and reverse is about 3.5:1 that means for every revolution of the wheel the engine will try and turn almost 12 times... Not only will it be bloody hard to do with a car without a seized engine, nigh on impossible with one which is... but you're likely to screw you gearbox at the same time...

If you're going to try this method, then stick it in 4th an push forward, you then only have the final drive ratio to contend with...

( ps this is why you should bump start cars in hi gears, 2nd, 3rd or even 4th puts a lot less strain on the transmission )

[benbarnes]

It will be VERY difficult to push the car and turn the engine when it's in reverse, the gear is WAY to short to do this...

Think about it, the FD is say 3.4, and reverse is about 3.5:1 that means for every revolution of the wheel the engine will try and turn almost 12 times... Not only will it be bloody hard to do with a car without a seized engine, nigh on impossible with one which is... but you're likely to screw you gearbox at the same time...

If you're going to try this method, then stick it in 4th an push forward, you then only have the final drive ratio to contend with...

( ps this is why you should bump start cars in hi gears, 2nd, 3rd or even 4th puts a lot less strain on the transmission )

Well I had previously been pushing it back and forth and 4th gear, I will stick to doing it that way then

[lildeucecoop72]

I know someone who had a TR3 with a seized engine. They rolled it down a small hill and then put it in fourth. That cured it. Not sure if its recommended though. I'd perhaps check with others and save this as a last resort.

[Yoda]

If you have the head off, use a piece of wood and a large mallet to tap on the top of the seized pistons, this may be enough to start them moving! a full rebuild would still be recommended though.

[benbarnes]

Although that idea of pushing it down a hill and putting it in gear had crossed my mind, my mini isnt in a state to do that, as its in bits and has no brake or clutch fluid in. I'll give the hitting it with a mallet and peice of wood idea a try though. Please keep the ideas and advice coming, thanks.

[mk3 Cooper S]

If you have got the head off, spray around the edge of each piston with "plus gas".

Leave overnight and the get a big breaker bar on the crank pulley.