87 camaro no heat
 

K it worked like a month ago when i used car, but when used it last week was blowing cold air, its not fogging the windows or anything on defrost so i dont think its the heater core, was low on coolant so i filled it...i think it got luke warm for a minute then went back to cold....when radio is off, i cant hear so kinda liquid moving around and making noise from behind dash on passenger side. im not sure if somethings clog or not? or maybe i just need new thermo? any one can help? car reaches normal temp 2 right in middle

If the temperature of your water is normal then its not the t-stat.

I would say, make sure you can hear the flappers moving when you slide the controls. The hot-cold slide moves a cable driven flap. If you pull off the lower dash panel on the passenger side, you can see it. Mine popped off once.

Check to make sure that control valve, (mushroom thingy on passenger side of motor above valve cover) has the vacuum line connected and thats working. Its easy to by pass it with running a line straight from the heater core connector on the firewall, to the water pump (with a barb fitting) or the radiator. Other one goes from the core to your manifold.

I would check those first before I say its clogged.

get the car up to operating temp, feel each hose going to the heater core (one is in, one is out) if the in-hose is hot, and the out-hose is cold/mildly warm, you either have a plugged core or a heater valve not opening

the flappers u speak of u mean u can actually hear something like click open and closed? cause when i move the lever from cold to hot i can feel as if the cable is on there but i hear no noise....ill go look into it now and report back

heater valve check the vacume line