possible heater core bad???

[caprisecca]

okay so i tried searching but didnt find anything quite like this. so basically my heat has been randomly blowing cold and hot. for instance i was driving it the other day and had good heat for about 30 minutes then all the sudden it started blowing cold. so i turned it off. next couple days it was working fine but it seems to be blowing cold now more often than not.

i did try to flush the coolant and changed the thermostat while i was at it and it didnt seem to help any. u guys got any ideas? is this my heater core going out?

[Movin]

Did you flush the block and the heater core separately? Heater cores act like a coolant filter for festivas. You were back flushing ?

[caprisecca]

I drained the block and rad off all coolant. filled it back up and added the cleaner u add in the rad and idle for ten minutes with heat in high. Rinse and repeat.

[Movin]

Try just the heater core..unhook the hoses and use a garden hose in both directions by just holding the end of the heater hose to the garden hose. Also make sure the nipples are not plugged. If you have a really old original heater core it is probably getting weak. You could possibly clean out gunk and uncover a leak, the only fix would be a new core and you would have to hook the two engine nipples together until you can get a heater core. Heater cores are rather entertaining to replace too.

[caprisecca]

What nipples where r they

[Movin]

One nipple is right above the starter solenoid and has a heater hose that goes to the firewall. You will notice there are two hoses on the firewall, follow the other one back to a nipple on the intake manifold.

[caprisecca]

Thx I will do that