Based on the sounds of it - my engine needs new freeze plug(s). It only leaks coolant when the engine warms. If I choose to let this car sit for an extended period (6 months or more) before I get it repaired, will any damage to the engine result ?

 

It would be pretty rare for a casting plug to leak (freeze plug). You most likely have a leaky hose, pressure cap, or at worst a coolant seal leaking. It's never a great idea to let it sit with anything inside the combustion chamber but if you cycle the engine every couple weeks with some oil put into the housings you'll most likely dodge any bad erosion/rusting.

You might want to go to an auto parts store such as autozone/advance and rent a coolant system pressure kit. You can connect it to the top of your filler neck and pump up the system pressure, all while looking for the leak. You'll likely have one of the outcomes below...

1) If for some reason you cant find it leaking, it's the pressure cap. If you can inspect the rivet and the rubber seal for tears/defects.

2) A hose will be cracked, a hose clamp under-torqued, or a mating surface weeping (could also be your waterpump).

3) Leaking pressure but no visible coolant leaks. It could be your coolant seals and in a very rare chance your casting plugs (freeze plugs). I would after this test start the engine, from a cold state, and do the champagne test...

Goodluck....

 

^^^^ good advise.

if there is any doubt about the engines coolant seals, put some oil in the combustion chambers, the rotors and seals are iron, so if they sit in water, they do rust together