I had clouds of steam on startup and wet plugs. HAIL MARY - - - - -> alumina seal+oil leak sealer. It worked for 5 years, then I had to do it again.

Sat for 12 years ? ------> things could sort themselves out if you just change fluids and run the engine.

 

Man...... You guys have been super helpful. I thought I would provide update......but actually need advice too . Got the 12A unfrozen with persistence and marinating in MMO. I got good fuel flow to Carb with fresh gas. Low and behold it fired up. You would have thought a bomb went off by the amount of smoke (not steam from what I can tell). The smoke was coming from everywhere. I turned off car after about 2-3 minutes because neighbors came over and it looked really bad---I mean bad,bad.. The car kept producing smoke heavily for probably 10-15 minutes longer (I can only assume it continued to burn MMO. Then, I noticed some seeds and debris inside of tailpipe from what I am sure is an old mouse house. A clogged exhaust? might explain the smoke coming out of engine bay and seemingly everywhere else... but there was still some smoke coming from tailpipe. The question i have at this point is does anyone know of a way to clear/test the exhaust system without removing the whole system? Can a mouse get up into a housing from the tailpipe? I am thinking a shop vac at tailpipe wont do much. I want to continue to run the engine but do not want to burn down the garage and car. I am thinking about running engine for short 1 minute intervals (after dark ) without getting the engine too hot in order to burn off the oil in the housings. Am I crazy to do that and risk a fire? Maybe a fire is not really an issue but all that smoke has me concerned.... If all the smoke was just coming out of the tailpipe I would not be as concerned with the smoke because I knew it would smoke like crazy. Thanks for your help!!!

 

These engines don't put out that kind of smoke for 10 minutes from just burning off the MMO, and remember that MMO is just ATF and petroleum distillates, which is what makes it a good penetrating oil, and also allows it to be added directly to fuel. The smoke you're getting is not from that alone - it's either burning oil sucked past the Oil Control Rings, or Coolant sucked past the Coolant Seals on the housings.

Either way, this is easy to determine by putting your hand in front of the exhaust pipe and then smelling the smoke residue. If it's white smoke and sweet smelling, it's coolant. If its bluish smoke and oily,... its... engine oil. You should also check your Coolant level in the Radiator and the Oil level on the dipstick to see what's missing.

A clogged exhaust - even the worst mouse house - would prevent the engine from starting and running. I doubt its an exhaust restriction, and those don't cause smoke.

 

What @LongDuck said. You have a few issues from the car sitting. Probably some mouse nest in the exhaust and most likely coolant seal failure based on the rust on the plugs you pulled. You can try running it to clear things out from the exhaust but be mindful of not overheating the engine by watching coolant and oil levels and the temp gauge. I've seen 12As recover from stuff like this. Its amazing how tolerant they can be to sitting for long periods. You will need to educate your neighbors and the fire department about whats happening though. Getting the exhaust good and hot should burn up and blow out any nest thats in there. Then you can see if the smoke is oil or coolant and move on from there. Sometimes coolant leaks can be "repaired" with alum a seal in the coolant but its not highly recommended as it can cause issues with clogging unintended areas as well.

Worst case is you will have to pull it apart and refresh the seals during a rebuild.