Simple ?

[KC96LSC]

I"m not in the best of health so it's going to take me 2 days to change my thermostat. Will my engine be ok sitting overnight with no antifreeze in it? going to get down to mid 20s tonight.

Greg

 

[Right on the Mark]

Only str8 water freezing is the problem. Empty(antifreeze) engine is not a problem. No different then your air cooled lawn mower sitting out.

 

[soduka]

If there's no water to freeze there's nothing to expand to crack your block

 

[KC96LSC]

If there's no water to freeze there's nothing to expand to crack your block

That was my first thought but I wasn't sure if there might be some left in the block. Just overly paranoid.