Coolant leaking from seals on Buick 231 questions?

I have a 1979 Buick 231 swapped into my CJ5. I just finished the clutch. I started it and got underneath to adjust the linkage because it was dragging. I noticed it was leaking coolant from the seal in the picture. This is the drivers side. It was initially brownish coolant. It stopped once the motor warmed up. I drove it around and everything seemed fine. Got up this morning and there was a small puddle of bright green coolant again. My questions are #1 is coolant surrounding this seal? I thought oil would be in this area. #2. If this is just a leaking seal and not a symptom of something bigger, how do I replace this? Thanks for any tips. Zech

 

Are they leaking on the other side also? If so, it probably did see a little freezing. Having them rust out isn't uncommon and they are relatively easy to replace if you can get to them. One's like the one under the motor mount will take some time.

You should monitor the oil closely. If it did freeze, it could have cracked the block also with water in the oil. At that time it's likely a new block.

 

Just FYI - they are called "freeze plugs" in the vernacular, but they are actually there so that the casting sand can be removed from the coolant passages in the block. It's true that they tend to pop out if water in the block freezes, but there is no guarantee that the plugs will pop out and the block won't crack if it freezes.

Yes, the coolant passages are behind it.

Get the replacement parts before you start. Drain the coolant. Drill or punch a hole in the plug, put a lever in the hole and pry it out. Clean the block sealing surface as best you can. Put a little Permatex #1 on the sealing edge of the new plug and drive it in with some kind of improvised driver that fits into the cup of the plug. Refill the coolant.

 

Great time to flush out the block while you have the plugs out. Very common on these motors to rust out the plugs if motor has sat dry for any length of time.. Best to replace the leaking ones instead of trying some kind of block sealer. A block sealer may work short term, but it also gums up everything else in the cooling system.

 

Its only on this side. The one in front of it looks like it is weeping some too. The passenger side is totally dry. She sits in a garage so I don't think it gets to cold. It did freeze the other night but nothing crazy. This rig has been sitting for close 10yrs before I bought it. Everything on it that can leak, leaks. I thought I had fixed all the leaks and then this one popped up. Sounds pretty straight forward. Thanks all.

 

There are different sized (diameter) freeze plugs. Be sure to get the correct ones and, get some extras. I had to replace 2 on an old Ford FE engine. Damaged 2 of them during installation and had to get more. As stated, a little sealer around them when you put them in. I used an appropriate sized socket as a driver for installation. There may be a better tool out there. Drain the coolant from the block before you start.

Also, the plugs are often available in either steel or brass. The debate over which to use is one that has plagued mankind for centuries. Good luck and be patient with it.

 

Many times over the years I've had great success with this leak sealant when I wasn't in the mood for, or couldn't afford, more substantial repairs. When the system is cool and unpressurized, you put the stop leak directly into the radiator and then go drive it around for a while. It should seal this seep up pretty easily.

http://barsproducts.com/catalog/view/5-powder-radiator-stop-leak-conditioner-g12bp

As for coolant getting into the oil system, from my experience, if coolant does get into the oil, it won't look like oil on the dipstick, it looks more like a vanilla milkshake. The water gets all frothed up with tiny air bubbles suspended in the oil making it look milky.

Good luck.