Freeze plug problems?

[942wdSC]

I have a 94 4.0 liter 2 wheel drive ranger and i got a coolant leak i'm pretty sure it's the freeze plug on the drivers side under the motor mount but can't fully see did these motors ever typically do this (It has 178,000 miles).

 

[tinman_72]

Many motors typically do this, especially those that reside up north.

 

[alwaysFlOoReD]

It really depends on how well the coolant system has been looked after. Coolant should be changed every 2 years. Before I knew that I never worried about it..... I've also replaced lots of freeze plugs, including some on a 4.0l.

 

[sgtsandman]

Rust does get to them over time, so it's not unusual for them to rust out by now.

 

[black_demon69]

My suggestion is to replace all of the freeze plugs with brass freeze plugs. Unfortunately the easiest way to do it is to pull engine.



Reason to replace all is chances are that if one failed more will fail in short order after that one is replaced.

 

[RonD]

I have a 94 4.0 liter 2 wheel drive ranger and i got a coolant leak i'm pretty sure it's the freeze plug on the drivers side under the motor mount but can't fully see did these motors ever typically do this (It has 178,000 miles).

Welcome to TRS

Yes, not uncommon at all on any car/truck engine

Freeze plugs are used to plug the Core Holes in the block, engine blocks are made by pouring molten metal into sand molds, after they cool the sand must be remove from inside the cooling passages, so these "core" holes are used to get the sand out.
Engine makers use the cheapest method to plug these holes, which are core/freeze plugs like you have now, and they can last the life of the engine, so not a bad choice to use
But.............. these can rust thru and leak as well

As said maybe because coolant wasn't changed every 2 years or could be external, salted roads or ????


I prefer to replace these with rubber expansion plugs if engine will remain in the vehicle
Like this: https://www.dormanproducts.com/p-1163-02607.aspx

Easier to install in tight places than stock or brass plugs

They come in different sizes, so you need to match that for your engine

If engine is out then I would replace them all with brass plugs, they last longer that stock plugs and much cheaper than rubber plugs


"Freeze plug" came from years and years ago, and name just stuck, they will pop out if water in engine freezes, but block can still be cracked by the freezing water, they are not there for safety reasons, lol.
They are there to plug the holes made to get the sand out, simple as that

 

[alwaysFlOoReD]

x2 on the rubber plugs if the engine remains in the bay.