12 grader coolant loss into oil pan

Have been working on the 9U which was the subject of this thread http://www.acmoc.org/bb/showthread.php?17111-D6-9U-running-HOT-and-radiator-cleaning&highlight=radiator

It had some moisture in the crankcase when we were last running it hard in the spring, but when I started it up, the oil stayed black and just running it back to the shop to work on a stripped track tension adjuster, it didn't overheat or have any trouble. Of course I was just idling along trying to keep the track on, not working it much at all. It has been sitting for a week or so since I had to get the screw from Florin in California. Installed the screw and started it up this afternoon and noticed the radiator was about 3 gallons low........sure enough the oil is milky, thin and milky though. There is an external coolant seep on the head gasket area that I think is most of the leakage problem, but the milky oil is new.

So, I put in 3 gallons of antifreeze (it's getting below freezing here now) and a bottle of Dike and let it run a while this afternoon. It is in the shop, so I'll probably put another bottle or two in it and see if it'll take care of the leaks before I replace the head gasket. If it holds, I'll change the oil again.

You might be able to plow snow just fine with a good dose of stop leak if you don't have compression gas building up in the radiator. You can rig up an adapter using an injector hold-down nut to put shop air pressure into each cylinder with the piston at TDC compression stroke and see if any comes into radiator in which case a precombustion chamber is fairly likely to be the problem and you can remove and check the seal without removing the head. The air pressure test will identify which precombustion chambers you should pull out.

If no bubbles into radiator, assume it is liner seals and the stop leak has a good chance of sealing it off.

Warning for use of "stop leak" if it is leaking past liner seals.

I had a 1370 Case that I "dosed up" with Bar's Stop Leak-------turned out to be leaking past the O rings on the sleeves. Stop leak was very abrasive and circulated throughout engine------had to replace all bearings------turn the crank------replace camshaft and bearings.

Hate to disagree with CC (he is a doctor in addition to being a master mechanic)--------but be careful with stop leak in a wet sleeve engine.

Check it for abraisve qualities before using.

Delta Dirt

Stop Leak products are also known to do a nice job of stopping up oil passages when introduced into the lubrication system.

Got it buttoned back up yesterday. Torqueing the head slowed the seep down to a wet place that I think will stop in time. Coolant level is holding overnight at least. I got about 1/8 turn on most of the nuts, but only by loosening first and then retightening to torque spec of 100 pound-foot on the small ones and 150 on the big ones. Not sure when the specs were increased, but I had those written in my SRB.

The pony head gasket was damaged in the fire ring area. Almost looked like it had gotten smashed before installation and used anyway. An arc about 2" long around the cylinder bore (about 6 o-clock to 9 o-clock) was smashed like the piston hit it, but that should be impossible...

Anyway, I found another one in good shape that seems to be working just fine. Oh, the time consuming part of the pony job was digging the crud out of the head and block water jacket! Once I raked all I could out of the block, I took the air hose and put air into the bleed cock on top of the pony and it pushed coolant out of the pony quite nicely. After that, I felt better about running a thin pipe into the block ports and blowing to loosen up more. A couple repeats and the coolant would come out clean. I know there's more in there, but that is going to have to wait for another day when I can lift the pony off and do it right.

Oh, the freeze plugs were very thin even though only one was leaking yet. There are 7.....took a couple trips to town because the ones on each end were covered with dust still.

Started it up and let it warm up and then drained the oil. There is still a little contamination in the new oil, but I think it will be fine to run it and drive that moisture out.

Im glad to hear things went well. Nice feeling to have an easy fix once in awhile.