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Oh No--Snapped Off End of Crankshaft Bolt


BoostedBimmer
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While I was trying to rotate my frozen motor using a breaker bar with a 22mm socket on the bolt on the end of the crankshaft (and yes, I had all spark plugs out and sprayed the holes with Wd-40 and Marvel Mystery Oil all week), I was finally able to get the motor to rotate, and then all the sudden, the bolt snapped off!

 

It looks like I have to take the whol motor out now :[

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I don't think it much matters what you do to a locked up motor but the rings are what usually sticks to the cylinder walls from rusting. Back and forth is the way to do it. Its going to have to be rebuilt anyway I hope you didn't think you could just run it with stuck rings. That crank bolt doesn't bottom out so removing it isn't as hard as you think, you might even be able to turn it with your fingers.
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Atf always worked for me on any stuck pistons.The head of the bolt is what tightens against the pulley.

As indiana says most will come out easy or with a punch.

Edited by rcm
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Oh thanks guys, I didnt realize I can get that bolt separately (I just looked it up on the parts manual)...Im gonna get a new bolt, and then drop the oil pan and see whats up. Im also replacing the whole head with a new non-jet head (due to blown head gasket)...
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Go to Harbor Freight and buy an engine stand, like $30. Pull the motor, mount it sideways on the stand, tear it COMPLETELY down. If it's really stuck like that you MAY get away with a good hone, but more likely will be boring it. Spending money on gaskets to put it back together now is a waste of money. You'll be replacing them again when it won't build compression (if you get it freed). And if it popped a head gasket you may have AF in the pan and you'll need to check the bearings. AF eats them.
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One should never try to turn an engine that you know the rings are stuck to the cylinder. It can only hurt things like crank journals, etc... The only exception is if you must turn the crank in order to get the parts off. In any event, you should only do that with the head and oil pan off, with room to spray rust inhibitor on the obvious affected area. You should then also spray all friction parts such as bearings with light oil so there is less chance of damaging them. You can spray the sides of rods and main caps on the journals so some oil gets in.

Do not turn the engine to run the rings past the bad spot. That can cause damage deeper in the cylinder wall than before, which requires more boring to clean up.

You really just want to push the stuck piston up and out if at all possible. One motion just to get it out.

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Ok, I dropped the pan,and am attaching the following pics. There was no metal in the pan, just the classic milkshake/oil mixture. The bearings appeared ok, and everything seemed tight. As far as rust goes, I really only saw some surface rust on the rods (as you can see in the pics). Im gonna take the head off next (Im getting a new non-jet head), and see what the pistons/rings look like. If the cylinder walls are ok, do you think I might be able to get away with possibly just replacing the rings (obviously if the clearances check out ok too)? Ill probably change the bearings too since the pan is off. Im pretty sure this is an un-opened motor with std clearances.....

post-16117-0-64006700-1331681188_thumb.jpg

post-16117-0-98870200-1331681207_thumb.jpg

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rebuild time, if it was milkshaked it was possibly overheated. The rust needs to be cleaned off everything. If there is flash rust on the rods then there is probably rust in the bores that are exposed to the crankcase are probably rusty too.
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I take blocks like that and put them in storage to mess with when parts get more scarce. You can find better blocks for cheaper than it might take to rebuild that one.
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  • 3 weeks later...

Ok, I took the head off, and sure enough, the piston walls are pitted/rusted (the piston tops were clean though) and the motor is still totally seized. I also found the crack on the (original) head between the no. 3 & 4 cylinder, which resulted when I overheated the motor years ago...

 

I plan on pulling the motor and getting it rebuilt down the road. In the meantime, I might plan to just get another used motor and install it for the time being..

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