# Z3 1.9 2001 Heating and Cooling Problem



## highlysceptical (Mar 17, 2009)

I have a Z3 1.9 2001 which I have owned since 2002.

Recently, the heater has stopped working properly. Even when on max heat, it normally blows cold, but just occasionally produces a few seconds of warm air - but nowhere near as hot as it used to get.

The engine heats up quickly, and the temperature gauge sits rock solid in the middle. The top radiator pipe gets hot, but the radiator matrix is cold, the fan does not come on and the lower pipe just gets mildly warm. I am assuming it is just picking up heat from the engine since there doesn't appear to be any water flow through the coil.

Also, I have not felt any heat in either of the pipes feeding the heater control valve, but the pipe that passes through the bulkhead next to the heater control valve sometimes gets warm (see attachment)

Can anyone suggest what might be going wrong?

Thanks in advance for any suggestions.


----------



## highlysceptical (Mar 17, 2009)

I have now discovered, by trawling the internet some more, that the thermostat is on the exit end of the radiator, which could explain a hot supply hose, a cold discharge hose and no apparent flow through the radiator if it is stuck shut. But would that explain why I am not getting any heating in the car? I guess it all depends on the configuration of the water circuits.

In any case, is there any way to diagnose which part is faulty, or do I start with the thermostat and hope for the best?


----------

