1994 2.3L coolant leak out of block?

[antonio]

Hello all,

I've been chipping away at my 1994 2.3L, can you please diagnose/help with this coolant leak out of the engine? Where is that leak coming from, a freeze plug? How bad is this and what should I do about it?

These pictures were taken a day after replacing the heater core and spaying down the area, so I'm pretty sure it is not just random splash. I'm currently running stop leak (heater core temporary non-fix). I don't think I'm losing a lot of coolant, so I could run like this for a long time.

What if I were to just plug the leak from the outside with some j-weld or similar (disabling the plug, but it doesn't really get that cold here in coastal Oregon)?

Many thanks in advance,

Antonio

 

[RonD]

Yes, that looks like the "core" plug has rusted thru.
Often called a Freeze plug, but has nothing to do with freezing
i.e. if block freezes it will crack, the plugs would pop out but block would still crack because of water in lower areas

Those holes in the block, and heads, were there to get the sand out after the block was cast with hot metal, they are needed to get out the "core" sand from the mold, so they are core holes.
Read here for more info: https://en.wikipedia.org/wiki/Core_plug

You can drain the coolant and then knock out the leaking plug, just tap on an edge and it will usually rotate so you can pull it out, if it falls inside it won't hurt anything, it can't block coolant flow, it will just sit at the bottom of blocks water passage

You can get rubber core plugs that are easier to install in hard to get at locations.
They look like this: https://www.mbca.org/sites/default/files/7009016_FreezePlug.JPG

All auto parts stores carry theses, get one of the correct size.

The rubber ones work the same as the metal ones, metal ones are just cheaper, which is why car makers use that type.

 

[alwaysFlOoReD]

^^^ I agree, use the rubber ones. Just make sure it is installed square in the hole.

 

[tomw]

Only one thing to remember with the rubber plugs: Keep the coolant at 50/50 water:antifreeze. The bolt that compresses the rubber to squish it so it seals, and deforms to hold it in place can rust if you don't. It is a pretty small diameter bolt, and will rust away a lot quicker than a new 'freeze plug'. The plug you need is wide open for replacement, but I would suggest looking at all the others you can find, as the ALL have been subject to the lack of maintenance that caused the corrosion and leakage.
If one is bad, you can bet the others are not that far behind. Installing the proper coolant may save them from failure, but I'd want to KNOW rather than take my chance on a guess. Your choice.
To install a metal replacement(Dorman likely), you will need a hammer and a driver that will span the diameter of the plug(for easiest installation), but you can get by with just a hammer if you can get it started. The edge of the plug should be lightly coated with Permatex type sealant before installation so it seals quickly. It is not fun. The plug will want to rock all around as you try to get it to start. If you can find a slug of metal that will fit into the new plug, and hammer on that instead of the edges, it is a lot easier. A seal driver kit may have what you need.
tom

 

[Mark_88]

I believe there are others on the driver side of the engine that you might want to replace while doing this job. The exhaust is harder to remove to make the job easier but it looks like you can almost get at that one without too much fuss...but it might be hard to smack something into place...

Maybe a short piece of pipe that fits inside the plug and won't get caught on the edge after you drive it in. Not that a piece of pipe sticking out the side of your engine will hurt anything...so maybe the rubber would be better if it doesn't involve hammering it into place.

 

[MrGiggles]

In high school, I popped a core plug behind the alternator on the 305 in my Chevy pickup. I lost almost 3 gallons of coolant across town, but made it into the parking lot.

I signed out just before lunch, had my mom bring me the tube of Permatex Ultra Black I had at home and 3 gallons of water.

I cleaned out the freeze plug as best I could, smeared a bunch of Permatex in it, and signed back in for the rest of the day. After school, I filled it up with water and drove home. It didn't leak a drop. I fixed the plug that weekend, so I can't say how long it would have held up for.

Something like that may get you by for a while, but it's not a permanent fix.

 

[antonio]

Thank you all for being so awesome and super helpful!!!