Heater
- Thread starter Nickskip
- Start date
I am having a similar issue. I thought I would post here since there have been no replies to the original post.
I’ve had the car a couple weeks. The heater has never worked well but the AC was working ok. Today it’s about 30C outside and I had the AC on, driving on the freeway. The AC stopped blowing cold and a short minute later the heater came on smoking hot like I’ve never seen and would not respond to the temperature control at all.
I thought I might be overheating so I pulled over, but Engine temp seems normal, Right in the middle of the range and the engine bonnet is not even warm. I could touch engine cover and even the radiator was not too warm to handle.
I think it’s likely that the temperature control knob, or whatever it controls, has died, leaving the heat exchanger wide open. The knob has a switch or at least a detention at its fully closed position, and I’m not sure what that does.
On the plus side finally I have all the heat I could ever want. On the downside - it’s summer!
I’ve had the car a couple weeks. The heater has never worked well but the AC was working ok. Today it’s about 30C outside and I had the AC on, driving on the freeway. The AC stopped blowing cold and a short minute later the heater came on smoking hot like I’ve never seen and would not respond to the temperature control at all.
I thought I might be overheating so I pulled over, but Engine temp seems normal, Right in the middle of the range and the engine bonnet is not even warm. I could touch engine cover and even the radiator was not too warm to handle.
I think it’s likely that the temperature control knob, or whatever it controls, has died, leaving the heat exchanger wide open. The knob has a switch or at least a detention at its fully closed position, and I’m not sure what that does.
On the plus side finally I have all the heat I could ever want. On the downside - it’s summer!
The switch controls a solenoid valve at the back of the engine compartment which cuts off the hot water supply to the heater.
Your problem sounds as if the cold air control cable outer sheath is loose, and therefore requires full travel on the knob to do anything.
Remove the radio and pull the heater controls out for examination - it is also a good time to replace the illumination bulbs as a preventative measure.
Your problem sounds as if the cold air control cable outer sheath is loose, and therefore requires full travel on the knob to do anything.
Remove the radio and pull the heater controls out for examination - it is also a good time to replace the illumination bulbs as a preventative measure.
Not a repair I’ve ever made. Although I’ve seen it discussed various times and as Mike says it’s usually slack in the cable.
I found a great writeup by pelican with some debug suggestions.
The flow of water to the heater core is on/off controlled by the temp switch through a normally open plunger solenoid valve near the center top firewall.
You can wind up with full heat if the valve fails open, the electrical switch of control unit fails (or as in my case there is a problem with the wiring.) My solenoid had become unplugged! I just plugged it back in!
BMW Z3 Heater Control Valve Replacement | 1996-2002 | Pelican Parts DIY Maintenance Article
Is your heat not as hot as it should be? Your heater valve may be failing, Use this tech article see how to test and replace it.
www.pelicanparts.com