Montana 2000: Heater Problem

[fishhead65]

Heat comes and goes . It will be hot one minute then cold the next. Any ideas?

[1Bradymichael]

The obvious is low coolant of course......and maybe a bad thermostat

Heater core might be getting dirty thanks to the Dexcool turning to mud,so a flush might be in order.

These vans are not known for super heaters in the first place,so if the heater is compromised it seems all the worse.

Maybe also a dampner acting up and not allowing hot air in the cabin.

[jsdii]

Where could I find a how-to to get the thermostat off? Do you have to take the screws out of the bottom or does the top unscrew? I've got the same heater problem and wanted to try the thermostat before I had to take it somewhere.

Thanks
JD

[1Bradymichael]

Replacing the thermostat is fairly straightforward. Get as much stuff out of the way first so you have more room to work....and be sure to get a GM thermostat,as some aftermarkets are just a fraction of an inch wider and makes it difficult to get the thermostat housing over top of it,as you have to kind of have to do two things at once becuase of the way it sits in there. This would also be a good time to flush the coolant system with a 50/50 mixture of coolant.