htr not blowing hot

[sick touring]

hi all this is my first thred so please give me some time to get it right .i have a 1990 320i touring nice but the htr gets hot on idle but when driven blows cold and i have no idea .have replaced thermostat checked fluid both ok any help gratley recieved.

[Starmavin]

Sounds like you have a bad or clogged heater core solenoid valve, The soleniod is behind the right kick panel of the drivers foot well. At full cold setting, the solenoid gets energized and shuts off the cooland flow. When it gets partly clogged it lets slow moving coolant to pass (idle) and plugs up when fast moving coolant tries to enter (driving). Try a heavy duty coolant flush and adjust the temp dial from max cool to max heat while flushing the system.

[sick touring]

thanks i have a doner car and have removed the iten i think are they all the same and can i just replace this item without to much hassle