Freeze Plug Failure

[TFC]

Out on some errand this morning, truck running great, heard a loud distinctive "PING" followed by the strong smell of engine coolant and a very sharp rise in temp, shut her down quickly and drifted into a convenient driveway, opened the hood and this is what I found, lower freeze plug top missing, looks like it failed at the fold and the top blew off leaving the pressed in part still in there.  Never saw this before???   Anybody else had this experience???  Makes me feel like the other plugs maybe headed for this too as they were all change a few years back when the engine was rebuilt.

[Dodgeb4ya]

That's what the engine block core plug hole recess should look like with out the plug installed.

Improper installation..

The plug was not expanded enough...

[kencombs]

I don't see any remnants of a plug at all, just the machined step it sets on when installed.  As the earlier poster stated,probably not expanded correctly when originally installed.

[TodFitch]

Agree with the others: That “ping sound” was probably the sound of the plug hitting something as it left the engine compartment. Improperly installed.

 

For what it is worth that happened to me once when I was accelerating on a downhill freeway on ramp before the engine warmed up enough to have the thermostat open. With the closed thermostat and the high RPM on the water pump apparently there was enough pressure in the block (on a nominally unpressurized cooling system) to pop the improperly installed plug.

[wallytoo]

i posted about the same thing in my update thread a few days ago, although it was the plug in the head.  and i surmised it wasn’t put in correctly.

Edited September 15, 2021 by wallytoo

[desoto1939]

Suggest that you use the brass welch plugs and not the galvanized welsh plugs. Clean the inside limp and remove any thing that will not make a good seal can use some gasket sealed when installing the Flat welch plugs not the cupped plugs and do not use the rubber plug that has the bolt in the middle.

 

The rubber plug can be used in an emergency situation just like what you expereinced on the road to get you back home and then put in the proper welch plug.

 

 

Rich Hartung

desoto1939@aol.com.

[TFC]

Thanks, I did work on the rebuilt of this engine but did not install the plugs(installed by machine shop), did not realize just how shallow the seat is.  Todd, I did not consider the pressure that can build up when the thermostat closes, when it happen I was driving up a slight hill at about 50mph, yes she was working , makes total sense. Great information, thanks to all. 

[Los_Control]

Sigh note to self  .... replace my freeze plugs ... again.

 

I replaced mine with brass plugs, cleaned all the casting sand out while doing it.

Because I did not know any better, I installed them with the concave side in ... thats what they look like when installed?

 

I now know that you install them with the curved side out, then when you smack em with a hammer, the metal expands and makes a tight fit ... now the concave side is in and not out.

 

I already have new soft plugs here to correct my mistake ... hey ho they dont leak ... seeing your post, I better move them up closer on the list before hitting the road.

[White Spyder]

Mine sprung a pinhole leak a bit back. Turned into a bigger project than expected because of the oil line and filter canister. I used an impact hammer to make sure mine seated due to the cramped space. 

[TFC]

Poking around I found Dorman 550-023 is the right part#, this item is made of steel, anybody know the manufacture and part# for a brass version?

 

A brass version is Melling# MEP-14B

Edited September 15, 2021 by TFC
found answer

[Los_Control]

They are 1.5/8" brass welsh plugs. A google search will provide many results.

Here is a photo from Ebay they want $2.83 each.

 

 

[TravisL17]

I found a kit on Rockauto recently that says they're brass. I contacted the manufacturer to find out what comes in the kit. Company is QualCast and kit part number and contents are below. Price was around $18. I have not ordered one yet. Below is their reply to my email.

97-61B:

7 96-1625CCB     Brass 1-5/8 Concave Cup

1 96-1375CC       Steel 1-3/8 Concave Cup

2 96-375HCPP    Steel 3/8” Hex pipe plug

[Jim G]

Yup, sometimes they just rust out, I had one let go on the way home from a highway trip, shut it off right away, but over heated the engine and softened the rings, Dad and I replaced them, and then shortly after the higher compression took out the bearings (should have done the entire engine at the time but cash money was a bit of an issue at the time) I hope you don't have the same issue!

[TFC]

Yikes!!!!  I hope I don't head down that road!!!!

[Jim G]

11 minutes ago, TFC said:

Yikes!!!!  I hope I don't head down that road!!!!

I hope you don't either, you'll know soon enough if the compression seems low etc. Don't worry about it till you have too, was just a heads up of something to watch for. 

[Matt Wilson]

I had the same thing happen - machine shop had not sufficiently flattened the plugs, and one of them popped out and I lost all coolant.  Engine overheated big-time, causing a crack in the head and possibly breaking a ring (I found a broken ring when I disassembled the engine, which could have been due to overheating or installer error, meaning my error when I assembled the engine).  I went through the entire engine and replaced all the core plugs, including the one on the backside of the block and the one behind the timing chain.  I made sure to flatten them well and carefully. There were a few on the LH side of the block that I replaced with the rubber expanding type of plug.  Not intended to be a permanent solution, but I did drive it that way for several thousand miles, with no issues.

 

This seems to be a common place for errors, as modern machine shops aren't accustomed to dealing with these types of plugs.

Edited September 17, 2021 by Matt Wilson

[TFC]

Another Yikes!!!  Thought I would wait until the brass plugs I ordered came in before addressing this, think I'm going to put in the temporary rubber expansion plug now and see where I'm at with this...  FTR: My vehicle karma has not been good this summer, about a month ago a crankshaft broke in another old car I have, yes I did said crankshaft.