Posted by Jim Cash on September 25, 1998 at 08:05:42:
In Reply to: Heater Problems 86 - 535i posted by Tom Glassco on September 24, 1998 at 14:09:56:
: Need help solving a problem with the heater on my 535.
: When the engine first gets warm you can get lots of heat for about five minutes. Then after that it has a mind of its own sometimes giving a little heat, but mostly no heat at all. My car has the rotary dial with the temperatures (numbers) around the dial.
: I also have experienced the same problem with the Air Cond cool for a while then nothing. This mostly happens when it is very hot ouside ~90F. When it cooler outside the Air Cond. will freeze you out.
: Any suggestions??
Tom - most obvious things to check are:
- hot water control valve - on the engine side of the firewall. The daiphram inside usually fails and you get heat intermittantly. The core of the valve can be easly changed - 4 screws on tope and it comes out - not expensive to buy a new one.
- the small plastic vacuum tube from the engine to the cabin temperature sensor may hve become disconnected - or there may be a build up of dirt on the sensor. Sensor is under dash - just above the dreviers left foot (left hadn drive cars).
Otherwise you probably hve a problem sith the Main temperature control system.