heater problems...stumped

[jmd2914]

when i start my car and let it warm up, the heater stays cold until i start diving then it heats up almost instantly. anyone know what might cause this?

thanks

Joel

 

[RsStanG1987]

thermostat not opening till you put the car under-load. Low coolant or air in the system.

 

[BK_CAULEY]

has someone ever installed one of those restrictor valves inline in the coolant tube going to the heater core? i know some early 90's rangers and explorers came with them from the factory. and ive seen a few in mustangs. they where most likely aftermarket but ive seen them. sorry for rambling.