1999 Pontiac Montana 3.4 V6 Heat problem

i am looking at buying a 1999 pontiac montana the person selling it said that it was overheating and he was told it needs a thermostat also the heat doesnt work he was told that its because the thermostat is closed. he said sometimes it will kick on and work. im just wondering if anyone can confirm this could be the problem or if it could be something more major and if so what else it could be. Thank you

Tell the seller to replace the thermostat if he/she thinks that is all the overheating problem is.

There could be more behind the scenes here so be careful.

Granted, a sticking thermostat will cause a circulating problem.

Have a qualified tech inspect the van before you part with your hard earned money.

Ask for proof of a replaced intake manifold gasket.

If the original hasn't blown yet, it will. It's just a matter of time. All 3.4L v6s were/are suseptible to this problem.

Perhaps this has happened recently and is causing part or all of the overheating.

Is it losing antifreeze too?

when i went to pick it up there was no antifreeze in it which is why there was no heati put antifreezein it and it didnt overheat and the heater worked great but as i was runnung it i looked underneat and it is leacking a little antifreeze from the bottom i dont know what the cause is yet

You might want to get a coolant pressure test done before driving it around just in case the coolant is leaking from a gasket.

Look on the bottom of the oil filler cap for a light brown oil. If this shows up, the coolant may be mixing with the oil in the crankcase.

Some coolant leaks can be very difficult to locate.