Freeze plug fell out on rebuilt head (2 Viewers)

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Jan 31, 2007
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Location
WYLIE TX
I had the carb and head rebuilt and then did all the work myself. On initial start up i ran it for about 15 minutes. I noticed a small puddle of fluid under the engine at the back, i looked around and didnt see where it was coming from. The second time i started it i drove it around the block and i realized water was just gushing out, the rear feeze plug on the head had fallen out......i have never heard of this or seen this before. I went to the machine shop and asked the guy who did it ad he said that there must have been some excessive water pressure to push it out. That sounded strange to me. It looks like im gonna have to take the whole thing down again to get the plug put back in, any ideas or solutions? There is very little space between the firewall and the head. I used a toyota head gasket when i put it back together....
 
The freeze plug that fell out of the back of my engine the other day was absolutely mangled, rather than placed and slightly dented properly.

Actually, now that I recall, the other two had obviously fallen out and been rubber stoppered when I got it as well, so all of them had been done poorly.

It's certainly possible to futz those up on installation.
 
I good rebuilder will replace freeze plugs on a rebuild.

I never thought it was possible to mess up installing a freeze plug. But I recently discovered when your machinist doesn't have the right size on hand and leaves it up to you to install them it's fairly easy to not see 4 resulting in filling your new engine with coolant. And when I was calling around trying to find some locally one place was trying to tell me a standard size would fit it fine and work. So perhaps the machinist installed a "close" size and they didn't hold.
 
I'm not an engine builder, but have been told by engine builders that they normally use locktite on a freeze plug, perhaps your guy didn't?. Another possibility should be to use J B Weld on freeze plugs since that 2 part adhesive is sometimes credited with sealing cracks in engine blocks!!!
 
I'm not an engine builder, but have been told by engine builders that they normally use locktite on a freeze plug, perhaps your guy didn't?. Another possibility should be to use J B Weld on freeze plugs since that 2 part adhesive is sometimes credited with sealing cracks in engine blocks!!!

The theory behind a freeze plug is, it should pop-out when frozen water expands, rather the other alternative would be a cracked block.........

Installing some sort of super adhesive would only hinder the purpose.........
 
I had the same problem after a rebuild. The freeze plug must be a metric plug (the one that fell out was a standard) and shouldn't use locktite for reasons stated above. This may sound bad, but I made 3 cuts in the firewall to lift for clearance to replace the freeze plug, bent it back down, and then the heater covered the "damage." Just a cheaper alternative that won't be seen unless the heater is removed...
 
Use Toyota plugs and prep the block holes and there will be no worries........
 
I managed to get a rubber plug in, it ran for 20 minutes and didnt fall out...napa sells a brass expandable plug, im gonna order one as a backup....lets see how this works.....if these options fail gonna pull the head...
 
I managed to get a rubber plug in, it ran for 20 minutes and didnt fall out...napa sells a brass expandable plug, im gonna order one as a backup....lets see how this works.....if these options fail gonna pull the head...

It's a machine shop issue.
Same problem with my old f engine, it started with the water galleys, them the oil galley plugs started blowing out. I'm almost thinking that some plug kits are listed for Toyotas but are sae instead of metric.

Long story short, I had to pull the engine and replace all the plugs with ones that sor stocked, with exception of one, which they hammered into the block so hard, it cracked it from the top down to the oil pan.:mad: It's had an expandable rubber plug (and a little alumaseal) for about a 130k now..:meh:

There is a 2f waiting for when it finally gives up..
 
It's a machine shop issue.
Same problem with my old f engine, it started with the water galleys, them the oil galley plugs started blowing out. I'm almost thinking that some plug kits are listed for Toyotas but are sae instead of metric.
that is what happened with my rebuild, only it was the assistant who decided that the plugs that were stamped with inches in the bag marked metric would work just fine even though they did not fit tight....15 miles later all of the coolant was on the ground...:mad:...and 30k later my engine leaks oil from some odd places....Brandon
 
I had my engine rebuitl years ago, guy messed up alot of things. For one he didn't use the right shims on the main, so the bearigns got detroyed during the first startup and run in. this prompted pulling the engine, and he fixed it. Not very well I'll add, but that is a different story.

Anyways, he replaced all the freeze plugs on the first go around, but the second time he tore the engine down, he had to hot tank it again to get all the babbit out. This time he left the freeze plugs in, 4 failed on the next first startup. Something about the hot tanking, I was told, will make the plugs fail. My head one did not fail, but the one below it in the block did, against the firewall. We took the rear engine mounts off and loosened the fronts and lowered the engien until we could replace it through the opening provided when the entire tranny hump is removed. I'm not sure which is more work, removing the tranny cover, or the head, both take time.

Possibly they lied about replacement, not the first time someone has done that, and hot tanked it, sorry for the failure, it's a real PITA.
 
By the way, here's how not to install a freeze plug:

I replaced all but this one (because of access) on my F135 shortly after I got it, because they were leaking and one had been replaced with a rubber stopper.

It's really a wonder it lasted 5 years. And that it chose to give out while I was parked in my barn, rather than along the highway in the middle of the night!
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