Engine block soft plugs. - JeepForum.com

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post #1 of 7 Old 01-25-2005, 12:11 PM Thread Starter
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Engine block soft plugs.

I own an 84' Jeep JC7 w/ an in-line 6 cylinder that has about 500 miles on it after a rebuild. Everything under the hood is also brand new. The Jeep overheated after only a ten minute drive and had shown no previous signs of running hotter. When I checked it, I saw that it was missing one of the soft plugs on the driver's side of the engine bolck and spilling coolant through it. What are these for? What causes these to pop out? Is this repairable or does the engine block need to be replaced? HELP???

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post #2 of 7 Old 01-25-2005, 10:45 PM
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It's where they drain the sand after casting. It probably wasn't installed properly. Unless you ruined something overheating it, you should be able to simply replace it.
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post #3 of 7 Old 01-26-2005, 05:47 AM
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Return it to the rebuilder and have them fix it. That way they will know about it when they rebuild the next guys motor and hopefully make you happy by making things right.

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post #4 of 7 Old 01-26-2005, 05:48 AM
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Oh yeah. If the coolant system happens to build enough pressure the plugs can pop out.

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post #5 of 7 Old 01-26-2005, 03:15 PM
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They're dual purpose, they allow access to the interior passages of the block during the casting process and they also protect the block from cracking if the coolant were to freeze. Sometimes they're referred to as "frost plugs" for this reason. In rarer cases they'll pop out during overheating, but usually the hoses will let go first.

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post #6 of 7 Old 01-26-2005, 08:17 PM
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"frost plugs"
how about freeze plugs.
I got you covered
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post #7 of 7 Old 01-30-2005, 09:24 PM
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Forget the plug, throw a block heater in that bad boy

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