A magic cure for a seized engine?

robind

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I have always used warmed /hot engine oil poured into the bores! Over all probably costs more but I think I will stick with it!
 

andy_wilson

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Do you mean....

Will it bu99er up my seized engine even more?

Plain diesel penetrates as good as most fluids and will offer some protection from further corrosion as it soaks in.

If it is an outboard a rich fuel oil mix would be equally effective, say 25:1.
 
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Hi it all depends why the engine siezed in the first place,if it was lack of oil that did it ,it would realy be magic stuff to get it going again,if the engine has been dunked in salt water i find diesel down the bores left for a couple of days and the gentle turning by hand usualy does it,but you should strip the thing down if all else fails. chris.
 

Searush

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Re: Do you mean....

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If it is an outboard a rich fuel oil mix would be equally effective, say 25:1.

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THAT'S NOT RICH - it's weak!! Proper Seagulls run on 10:1 normally.
/forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif
 

Heckler

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magic potions dont work!!! if its seized the bits will have torn microscopic chunks off each other, only cure is a complete stripdown and find out what bits have been damaged and repair them. You can get the same the same results as the expensive potions with wd40, diesel and oil mix or any combination of similar things, only prob is that you will end up with freed off DAMAGED bits what ever you do. OK as a last ditch get you home solution BUT i guarantee you will only ever have a smoky lo compression engine. Bottom line, if its seized, save your money, strip it, repair it unless you are desparate to get home or out of danger.
 

Avocet

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Sounds like "snake oil" to me! I wouldn't be putting it in my engine. As has been said, if the engine has seized, it probably needs stripping because there is likely to be some damage that no amount of magic potion will cure. I'm not saying this stuff won't allow it to turn again but it won't fix it either. To be honest, I think diesel used in the same way would work pretty well too. (and that wouldn't fix it either)!

I'd also be wary of trying to turn an engine with an impact wrench on (effectively) the crank pulley nut, even if it wasn't seized. I think the shock loads on the bolt threads would be very big just due to the inertia of the crank and pistons!
 

William_H

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Just because a potion is expensive is no indication it is good. There are plenty of oil based liquids which will probably do just as well.

The problem with a seized engine (presumably been siezed for some time) is that the mechanical advantage of the crankshaft moving the pistons depends on the position of the piston. So when a piston is misd stroke it moves a lot with every degree of crank turn while when the piston is at top it moves very little for crank turn. So crank is not the best way to move a seized piston. It is almost certainly the piston in the bore that is stuck.
The best way is to pull the cylinder head and help the piston move with a carefully calibrated bashometer. (lumphammer). Aply turning pressure on the crankshaft while easing the piston down with the bashometer using a block of wood. (or belting hell out of it depending.......)
If you can't move the piston to free it. Try disconnecting the con rods if it is a multi cylinder engine and working on one piston at a time. If that don't work it is probably time for a new engine.
if it is an outboard the cylinder head is usually quite easy to remove.

Avocets mention of moving a crankshaft using an impact wrench reminds me of an embarasing story of my doing. It was a Mitsubishi van and I wanted to replace the timing belt. It looked to me like the bottom crankshaft belt pulley had to come off and there was a hex bolthead sticking out of the pulley. I tried every way to move that bolt both left handed and right handed. Finally I got a book on the engine and found ultimately that the hex head was part of the crankshaft and put in for turning the crankshaft. Not a bolt at all.
Now I have a split plug spanner to remind me of futile efforts.
good luck olewill
 

Avocet

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I heard the Coke story plenty of times from several people who swear by it for ordinary seized fasteners. There may well be some truth in it!
 

Avocet

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My brother has a Nissan Skyline and (apparently) the commonly accepted way of undoing the crank pulley bolt to take the pully off is to put a socket on it attached to a log bar and then wedge the bar against the chassis member and crank the starter!!!!!
 

RichardTaylor

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[ QUOTE ]
I have always used warmed /hot engine oil poured into the bores! Over all probably costs more but I think I will stick with it!

[/ QUOTE ]

Hot (very hot - but also very dangerous) is the way some engineers will unseize an engine, as the heat also "shocks" the engine and with the various expansion rates of the pistons, rings and block, the oil manages to seep through and break the "weld". This is best done on a bench rather than in situ.
 
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