Block Plug
Thread Starter
Instructor
Joined: Jun 2008
Posts: 122
Likes: 1
From: Turnersville New Jersey
Block Plug
I have a 1989 Corvette L-98 and I want to remove the block plug that is between #1 and #3 plug. The plug in the block has a square opening and I can not find a tool that will fit it.
Does anyone know what tool I need to use to get this out.
Thanks !!
Does anyone know what tool I need to use to get this out.
Thanks !!
Tech Contributor
Joined: Oct 2008
Posts: 3,729
Likes: 190
From: Custer, WI
Are you talking about freeze plugs?
When i knocked the freeze plug out of my buick to put in a block heater, i just used a hammer and a flathead screwdriver. Be careful though, coolant comes flyin out. I tried convincing my girlfriend to pound it out, but she wouldn't.
When i knocked the freeze plug out of my buick to put in a block heater, i just used a hammer and a flathead screwdriver. Be careful though, coolant comes flyin out. I tried convincing my girlfriend to pound it out, but she wouldn't.
Thread Starter
Instructor
Joined: Jun 2008
Posts: 122
Likes: 1
From: Turnersville New Jersey
No this is not a freeze plug. It is screwed in the block. I need to remove it to install a fan sensor. I will try to upload a photo of this plug.
Last edited by coco1950; Jun 18, 2009 at 08:49 PM. Reason: Attachment
Team Owner
Joined: Dec 2000
Posts: 21,094
Likes: 282
From: Phila., PA burbs
The hole is 5/16" if I recall correctly. I had a real tough time getting it out on my car. On the advice of someone on the forum I ended up going to Home Depot and buying a section of 5/16" square rod. I then cut a small piece to use as a "bit" and found a 12 point socket that fit snuggly on the end. I was able to get it out this way. It was still a major PITA as the rod isn't hardened and kept twisting. Make sure to spray it liberally with some type of penetrating oil.
Thread Starter
Instructor
Joined: Jun 2008
Posts: 122
Likes: 1
From: Turnersville New Jersey
Thanks that's a good idea. I know this plug is going to be tight so the 5/16 square rod sounds like the answer. Someone also said I should heat the plug until cherry red and let it cool, heat it again and put some motor oil on the plug to lube the threads.
Thanks for your help, I will let you know how I make out.
Thanks for your help, I will let you know how I make out.
Race Director
Joined: Dec 2006
Posts: 10,383
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Well if it's 5/16 then any 3/8 extension is only 6/16. If you used a 5/16 open end wrench as measuring calipers couldn't you make your own tool with a grinder or file by taking off 1/16 on two adjacent sides?
Race Director
Joined: Apr 2003
Posts: 17,700
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From: moraga ca
Thanks that's a good idea. I know this plug is going to be tight so the 5/16 square rod sounds like the answer. Someone also said I should heat the plug until cherry red and let it cool, heat it again and put some motor oil on the plug to lube the threads.
Thanks for your help, I will let you know how I make out.
Thanks for your help, I will let you know how I make out.
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Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Just keep in mind that these are pipe threads and the plug is tappered. So it looks like a "V" with the small end going into the block. You could also take a 3/8" extension and give it a small TAP with a hammer into the plug........should work. Use a breaker bar, you will need some leverage.
Use teflon tape when you reinstall.
....should work. Use a breaker bar, you will need some leverage.Use teflon tape when you reinstall.
Drifting
Joined: Dec 2005
Posts: 1,313
Likes: 2
From: High Ridge Missouri
Thanks that's a good idea. I know this plug is going to be tight so the 5/16 square rod sounds like the answer. Someone also said I should heat the plug until cherry red and let it cool, heat it again and put some motor oil on the plug to lube the threads.
Thanks for your help, I will let you know how I make out.
Thanks for your help, I will let you know how I make out.
The proper tool you're looking for are a set of male pipe plug sockets.
Race Director
Joined: Aug 2000
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Cruise-In II Veteran
Thread Starter
Instructor
Joined: Jun 2008
Posts: 122
Likes: 1
From: Turnersville New Jersey
Thanks for all this information. The plug is the block it is cast Iron and not aluminum so I don't belive I have a problem with that. I went to sears and several auto stores. No one carries that socket. I have made up a tool using the back end of a pipe tap which does fits into the plug. I will try to remove it tonight using heat if I have too.
I will let you guys know what happens.
I will let you guys know what happens.
Thread Starter
Instructor
Joined: Jun 2008
Posts: 122
Likes: 1
From: Turnersville New Jersey
Well it turn out great. I used the rear end of a tap and turned it with a stud remover attached to a 1/2 drive breaker bar. It was tight but it gave way and came right out. I connected the temp sensor and the car is running much cooler. Fan comes on at 200 and shut off at 185.
Guys thanks for all you help on this issue. This is really a great forum if you like working on corvette's.
Guys thanks for all you help on this issue. This is really a great forum if you like working on corvette's.