popped a freeze plug - MustangForums.com

Classic Mustangs (Tech) Technical discussions about the Mustangs of yester-year.

Thread Tools Search this Thread
Old 03-18-2012, 09:49 AM   #2
6th Gear Member
Join Date: May 2009
Location: PA
Posts: 5,228

"Freeze plug" is a misnomer. Since the "freeze plugs" have nothing to do with protecting the engine from freezing, it's entirely possible that your block could be destroyed by ice, with or without popping plugs.

These devices are actually core plugs, and the holes are the means by which the sand cores are supported when the block is cast.
2+2GT is offline   Reply With Quote
Old 03-18-2012, 10:21 AM   #3
4th Gear Member
scootchu's Avatar
Join Date: Mar 2009
Location: NJ
Posts: 1,110

Just replaced two leaking freeze plugs and while discussing the very topic 2+2 mentioned the person I was talking to said he has never seen a "freeze plug" pop when the coolant froze. So yes you could cause severe damage to the block and a freeze plug would never show it.
scootchu is offline   Reply With Quote
Old 03-18-2012, 01:08 PM   #5
4th Gear Member
scootchu's Avatar
Join Date: Mar 2009
Location: NJ
Posts: 1,110

What I would do is check the coolant with a tester just to see what temp it was good for and ease my mind that the plug just rotted and the block probably never froze. If you can't get the engine out to properly replace the plug right now go an get the emergency rubber plug.
Even with the plug behind the motor mount you can jack the engine up with a jack and 2x4 supporting the wide part of the oil pan. Undo the bolts, jack the engine up remove the top mount and get to the plug. Not fun, but doable. I don't know how long i would trust the plug. I just put one in my 67 and have heard people say they drove around forever with them, but i have read that they are just an emergency fix.
scootchu is offline   Reply With Quote
Old 03-18-2012, 03:15 PM   #6
1st Gear Member
Join Date: Sep 2009
Location: Kentucky
Posts: 83

I popped two of them last winter. Both behind the motor mount on each side. I jacked the engine up, removed the motor mount and put them back in. Nary a problem since. I think they just weren't in very good. They went in pretty easy.
Smokeybear31 is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Bad cylinder? Dathan V6 (1994-2004) Mustangs 4 10-05-2015 06:52 AM
2002 convertible driver window issue cr620 V6 (1994-2004) Mustangs 1 10-03-2015 07:39 AM
04 Mach 460 system, Installed Aftermarket HU, No Highs/Tweeters breaking Audio/Visual Electronics 5 10-02-2015 02:27 PM
Clear codes on '94 sn95 BOB ROME 5.0L (1979-1995) Mustang 2 09-28-2015 12:10 PM
91 vert tailpipe smoking MacSerio 5.0L (1979-1995) Mustang 3 09-27-2015 02:05 PM

03, 1966, 46, 66, change, cobra, fox, foxbody, freeze, install, motor, mount, mustang, plug, plugs

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Featured Sponsors
Vendor Directory

All times are GMT -5. The time now is 10:31 AM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.