I have had the thermostat & water pump replaced and the heater core flushed but still have no heat. the radiator cap is always cold but the temp still runs @ 160 to 170. could this be a bad radiator cap or heater core?
There are two hoses for the heater core, make sure both are getting hot. If both are getting hot, then you may have an air blend door stuck in the outside air (cool) position. If the blend air door is stuck, the dash must be removed to repair it. If both hoses are not getting hot, then you may have an air pocket in the cooling system, and the system needs to be bled. Good luck.
You probably have an air bubble in the system.
Burp the system at one of the heater hoses until you have coolant coming out.And make sure you have enough coolant in the system.
I had this same problem and i tried alot of things. Finally I flushed my heater core by unplugging those two lines that run from the front of the motor to the firewall. I took some radiator 10 min flush and dumped into just the heater core and let it sit. Then flushed with water and plugged back in line. Mine was a flow problem because once the engine was warm it I could feel better heat if I revved the engine. hope this helps.