coolant drain plugs in block
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Joined: Aug 1999
Posts: 55
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From: Escondido, CA
coolant drain plugs in block
I’ve been searching trying to find the coolant drain plugs in the block of my 99 LS1 without any luck. There are a series of equally spaced fully recessed bolts needing a 10 mm socket just above the oil pan, 4 on each side, the driver side one which is furthest back is just above the oil filter, then there’s one maybe 4 to 6 inches in front of this which is easy to get to, then another in front of this just behind the engine mount, then one in the front. I tried the easy one but it had a drop of oil on the end so it looks like this is for the oil galleys. There’s also a brass plug about the size of a quarter in the front which looks promising and another about an inch in diameter, this may be a freeze plug. I didn’t see anything else on the driver’s side, did I miss something?
paul
paul
Team Owner
Joined: May 2001
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From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
The bolts you're looking at (and loosening) sound like the cross-drilled main bearing caps. LS1's and 6's have 6 bolt main bearing caps on the center mains. I would look up the torque specs on these and re-torque. To my knowledge, we don't have coolant drain plugs anywhere. HTH
Robert
Robert
Racer
Joined: Nov 2002
Posts: 358
Likes: 3
From: philadelphia pa.
There are 2 coolant plugs in the block, pass. side is above the starter,driver side is right in front of the engine mount, you can reach this one without removing anything. You need a 17 mm.allen hex socket.I only removed a 1/2 gallon more taking the plug out.
Last edited by c5inphila; Jul 18, 2004 at 05:23 AM.
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
Originally Posted by c5inphila
There are 2 coolant plugs in the block, pass. side is above the starter,driver side is right in front of the engine mount, you can reach this one without removing anything. You need a 17 mm.allen hex socket.I only removed a 1/2 gallon more taking the plug out.
Le Mans Master
Joined: Oct 2000
Posts: 6,507
Likes: 722
From: Sausalito CA
In the old days, after draining the radiator, we used to remove thermostats and then insert a special nozzel to force water and air through the block.
Could still work on a C5, but I do not know for sure.
Could still work on a C5, but I do not know for sure.
Racer
Joined: Jul 2003
Posts: 460
Likes: 0
From: N. Potomac MD
Freeze Plugs - Not
I just read an article and learned (wish to share and contribute). Although we commonly refer to them as freeze plugs they are not freeze plugs and are not there to protect the block from freezing. They are there because the holes are needed to clean out the sand and other material after the casting process. The metal plugs just close and seal the hole. Be good all. 
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Drifting
Joined: Mar 2004
Posts: 1,437
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From: UNDER THE HOOD
Originally Posted by Corvette00Car
I just read an article and learned (wish to share and contribute). Although we commonly refer to them as freeze plugs they are not freeze plugs and are not there to protect the block from freezing. They are there because the holes are needed to clean out the sand and other material after the casting process. The metal plugs just close and seal the hole. Be good all.
