Blowing freeze plugs

dangerous06

dangerous06

diesel tech
Joined
Mar 24, 2008
Messages
3,564
Got an 07 5.9 twin turbo that keeps blowing freeze plugs! First lost the rear installed block plate. Then lost a side plug installed screw in style and now it blew a plug in the head right behind the exhaust manifold!
I checked for head gasket leak nope rechecked head studs all were 125LB 425 ARP 's
So any other ideas? This is a fresh rebuild 3000 miles on motor never over 50psi boost. Builder said he used Cummins freeze plug kit.
 
There are 2 different sizes on those plugs. One is like .010" smaller in diameter than the other. We ran in to the same problem with our machine shop a few years back.

Older plugs were part # 3922072 measure 2.275"
Newer plugs # 4938189 measure 2.285"
 
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The newer plug listed are used on the 03 and newer (common rail) blocks. The old ones fit the hole in the common rail blocks, but they wont stay put. Take one of the ones that blew out and measure it. That should answer your question.
 
tap into the cooling system and monitor with a pressure gauge on it, it should not pressurize under load/boost pressure. i had a 04 5.9 blow 3 different freeze plugs, under load each time, the head gasket was popped.
 
Thanks for that info guys!! Sorry I posted in wrong section can admin move to right forum!
 
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Snedge gets a brownie! It was the wrong size freeze plugs! Add a bad head gasket and that made them pop out with ease!
 
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