The heater in my 95 Z28 (118k) has a bit of an issue. It works but doesn't get near as warm as it used to before the head gaskets were fixed last Jan. When I'm driving in the morning it's just not that warm and sometimes I'll get better heat when driving in the city vs. the freeway. The temp rises to about 185 as normal, sometimes even hotter, but the heat just doesn't get as warm as it should.
Think this could be a thermostat problem? The car doesn't have a leak and I haven't had any issues with overheating.
Thanks

 

the heater core could be plugged or the flow regulator may have something stuck in it. the return heater hose has a regulator in it that limits the flow so the engine can warm faster and heater core works better. its basicly a disk with a hole in it that only lets a little coolant through. be a good idea to back flush that heater hose and flush or replace heater core.

 

also make sure your getting the door slam when you turn up heat. should hear a thump when you move heat dial from cool to warm and warm to cool.

 

Any tips on flushing the heater core?

 

i have heard guys using garden hose and light pressure, not running water very open. core is built to handle low pressure, like 5 maybe 10 lbs pressure. home garden hose can have some pretty good pressure 50lbs. would need to remove both heater hoses and tap into it. be best to unhook hose with restrictor at the heater core.