with Bill
Engine block drain plug broken
Thread Starter
Drifting
Joined: Oct 2001
Posts: 1,770
Likes: 33
From: Cohasset MN
2017 Corvette of the Year Finalist
2016 C1 of Year Finalist
Engine block drain plug broken
A few years ago when I tried to remove the drain plug on the right side of my '61 engine, the head twisted off leaving the remainder of the plug flush with the block surface. I fear that sediment will accumulate if I don't get the broken plug out so I can properly drain and flush the coolant.
I considered drilling a hole in the plug and after heating the area with a torch, using an easy out to remove it. I am afraid of damaging the threads in the block and want to do this the right way.
Any suggestions on how to do this or should I take it to an experienced technician that can do this on a lift?
I considered drilling a hole in the plug and after heating the area with a torch, using an easy out to remove it. I am afraid of damaging the threads in the block and want to do this the right way.
Any suggestions on how to do this or should I take it to an experienced technician that can do this on a lift?
Race Director
Joined: Jun 2006
Posts: 17,901
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From: Inverness FL
St. Jude Donor '07
i'm not sure that an 'experienced' technician would be able to do any differently than you.
but then i'm not sure i would be worried about it being broken off, most engine blocks are never drained....
Bill
but then i'm not sure i would be worried about it being broken off, most engine blocks are never drained....
Bill
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From: Close to DC
C2 of the Year Finalist - Modified 2020
This is not the end of the motor. I doubt that any large amount has built up so I wouldn't worry. Have you flushed the block since this happened? If not give it a try with a flushing agent. Although you will never know if all sediment is removed/dislodged. If it still worries you, take it to a trusted shop. 
Dennis
Dennis
Thread Starter
Drifting
Joined: Oct 2001
Posts: 1,770
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From: Cohasset MN
2017 Corvette of the Year Finalist
2016 C1 of Year Finalist
This is not the end of the motor. I doubt that any large amount has built up so I wouldn't worry. Have you flushed the block since this happened? If not give it a try with a flushing agent. Although you will never know if all sediment is removed/dislodged. If it still worries you, take it to a trusted shop. Dennis
DennisYou know how we baby these cars. I would prefer getting the broken plug out.
Race Director
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From: Camp Verde AZ
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Any sediment in teh block not removed by flushing will stay where it is, plug out or not.
The lower half of the cylinder doesn't really need much cooling anyway, the heads and top third of the cylinder are where most of the heat is generated.
Doug
The lower half of the cylinder doesn't really need much cooling anyway, the heads and top third of the cylinder are where most of the heat is generated.
Doug
Thread Starter
Drifting
Joined: Oct 2001
Posts: 1,770
Likes: 33
From: Cohasset MN
2017 Corvette of the Year Finalist
2016 C1 of Year Finalist
OK, Bill and Doug. Maybe I won't mess with it. After doing a search on the subject, I guess brass plugs or drain ***** would not be a bad idea to prevent this from happening.
Safety Car
Joined: Aug 2011
Posts: 3,578
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remove plug
I had the same thing happen to a 283 engine I had. It's a pipe plug. Not sure if it is a 1/4 or 3/8" size. I was able to find the center of the plug, use a drill a little smaller then the tap drill and pick out the threads with an awl. It would be very difficult to do with the engine in the car. I not only wanted to flush out scale but the only way to completely drain the block is with the plug out.
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From: Folsom CA
I would not worry until you pull this engine out for other service needs. You can flush it every time you change your antifreeze without ever pulling the drain plugs.
I pull drain plugs on the boat before storing every winter but it has no antifreeze and this is necessary. I do not recall pulling plugs in any automotive engine unless it was in the rebuild stage.
If you really get excited about this job you can heat the block with a torch around the plug then sweat in Wax around the threads. Just like sweating a copper pipe connection.
The heat will draw in the wax and release the gunk on the broken plug. If you use an easy out after the wax it may come out. I would not even try this in the car. No gain to be realized. Good Luck
I pull drain plugs on the boat before storing every winter but it has no antifreeze and this is necessary. I do not recall pulling plugs in any automotive engine unless it was in the rebuild stage.
If you really get excited about this job you can heat the block with a torch around the plug then sweat in Wax around the threads. Just like sweating a copper pipe connection.
The heat will draw in the wax and release the gunk on the broken plug. If you use an easy out after the wax it may come out. I would not even try this in the car. No gain to be realized. Good Luck
Burning Brakes
Joined: Jul 2007
Posts: 1,090
Likes: 26
From: Gasburg Virginia
Removing pipe plug.
Do not heat the plug all the way around. Only heat it in three evenly spaced spots. This allows expansion but does not over heat it so the threads don't come out with it. This works very will on removing plugs from aluminum castings. Dave
I would not worry until you pull this engine out for other service needs. You can flush it every time you change your antifreeze without ever pulling the drain plugs.
I pull drain plugs on the boat before storing every winter but it has no antifreeze and this is necessary. I do not recall pulling plugs in any automotive engine unless it was in the rebuild stage.
If you really get excited about this job you can heat the block with a torch around the plug then sweat in Wax around the threads. Just like sweating a copper pipe connection.
The heat will draw in the wax and release the gunk on the broken plug. If you use an easy out after the wax it may come out. I would not even try this in the car. No gain to be realized. Good Luck
I pull drain plugs on the boat before storing every winter but it has no antifreeze and this is necessary. I do not recall pulling plugs in any automotive engine unless it was in the rebuild stage.
If you really get excited about this job you can heat the block with a torch around the plug then sweat in Wax around the threads. Just like sweating a copper pipe connection.
The heat will draw in the wax and release the gunk on the broken plug. If you use an easy out after the wax it may come out. I would not even try this in the car. No gain to be realized. Good Luck
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From: Sitting in his Nowhere land Hanover Pa
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