poor heating

[2.8 30v]

Hi my 1997 2.8 has poor heating,only blowing Luke warm so flushed the system replaced the header tank as it was full of gunk, bleed the coolant system and its still only luke warm all hoses are hot,and the motor for the flap is working fine. Has anyone got any idea what's wrong ( a/c not working needs a regas I've got a leak in that and will sort later)

 

[bydand]

The Heater core is part blocked with the gunk sludge, try back flushing with a hose down one of the cooling pipes to from the heater core. Or/and the thermostat is stuck full open and under cooling the engine.