Freeze question

[ferret_airlift]

We had a particularly brutal winter, and my Cub froze. I've replaced the radiator, and the lower bolster (It had been repaired before I got it, and the freeze made it lots worse). Now it's starting rough, and water sneezes out of the exhaust drain when it turns over. The oil is also milky. Any chance that this anything but a cracked block?

[tst]

pull the spark plugs and check them for any sign of coolant on them, turn the engine over with the plugs out and see if coolant comes out

[ferret_airlift]

Okay, so definitely on cylinder 2 and 3, none on 4, maybe a little on 1, difficult to say.

[Urbish]

Yikes, that doesn't sound good. Probably time to pull the head and see the extent of the damage.

[Slim140]

If your bolster froze and cracked, your block probably did as well with the symptoms you describe.

[Jim Becker]

Most common external signs of freeze damage:
Head: crack more-or-less front to back. If not too bad, it may look like just a paint flaw.
Block: horizontal crack on right side, high, forward of the oil filter.

Based on your description, you will need to pull the head. MAYBE the head gasket is leaking (water out of exhaust). But no oil passages go into the head. So water in oil is strong indication of internal block damage.

[ferret_airlift]

Dang. I was afraid of that. I'll pull the head this evening and see what I can see. So assuming a cracked block, she's more or less scrap metal?

[Stanton]

...So assuming a cracked block, she's more or less scrap metal?

The parts that are damaged due to the freeze, yes. You can buy a used replacement engine, just like a front bolster. If you want to keep the Cub and use it, that's an option. If you're looking for a reason to scrap this Cub in favor of another, here's your opportunity. For future reference, a mix of 50/50 anti-freeze will keep most Cubs intact through winter.

[ferret_airlift]

Well, I need to mow in the incoming spring. My mix was weak, and I knew that, but I wasn't concerned. Then we spent a week at -30.

Replacing a block goes a few notches above my skills and available tools. The tractor has been good enough, unfortunately.

[Cubfriend]

Check with JP Tractor salvage at the bottom of the page for a reasonable priced block already hot tanked and bored or used engine.

[ricky racer]

Too bad you don't live closer, we could make a project out of and have you going in just a couple of weeks....

[ferret_airlift]

What are the odds a head gasket could do this? I pulled off the head, and I can discern no cracks, but it looks like the head gasket may have been letting water through

[Cubfriend]

Were the head bolts sealed around the threads when removed?

[ferret_airlift]

Not all of them, actually

[Cubfriend]

They go into the water jacket and need to be sealed with rubberized sealant. Some others might have a recommendation of what to use.