Help! My truck puked in the cold. Is it dead?

[freemonty]

I think I have good news. Here's what I did:

Tested the coolant- it tested to +5deg, so it's clearly not up to par and I need to replace it and it might have frozen when it was -15deg.

Tested the cooling system pressure. Without the engine running, it would not hold pressure and slowly dropped.

Then I pulled all the plugs, they looked wet, but it kind of looked oily rather than coolant.

I then turned the motor over without the plugs in to see if I'd broken any internals and to clear the cylinders. It turned over fine, no bad noises.

I checked the oil again and it seemed satisfactory, so I put the plugs back in and tried to start it and it started! It sounded OK, no noises and except for the first couple seconds it wasn't rough. I had oil pressure but I shut it down anyway and then checked everything again for leaks. No leaks so I hooked up the coolant pressure gauge and started it up again and according to the manual for the tester I let the engine warm up and it ran fine.

The system would not hold the 13psi that my cap specified but it seemed to level off at about 7-8psi. When I shut it down I noticed a very minor hissing and I found a radiator leak on driver side upper corner. It was minor, just bubbling, not really leaking.

Soooooo, that's where I'm at now... I haven't actually driven it yet, but I think tomorrow I going to take it to Autozone in the morning and grab some radiator stop leak and see if it will plug that small issue. Other than that guys I don't know, nothing seems particularly wrong with it anymore....

Anyone got any theories?

By the way, it's up to 25deg here now and yes, I do drive my truck year round here in Chicago.