Expert: John Kingery - 11/30/2008

Question
in the winter i get heat drivers side..ice cold passenger side changed control panel still the same.

Answer
Sounds like a marriage joke, but I'll pass on that......

There are two separate heater cores tied together on this model.  (I just replaced the heater core on my wife's '95 e38.).  It sounds like the heated engine coolant isn't travelling through the passenger side of the heater core.

Could be a blocked heater core, but more likely a bad heater core valve.  It's mounted to the firewall behind the engine.  Trace the heater hoses coming from the firewall to a component towards the drivers side.  You might be lucky and have only a pinched hose.

Getting those short hoses on and off is difficult and maddening, but beyond that changing out the valve is straightforward.

If you want to test before you buy a new valve, get some heater hose, and replace the lines opposite, so that when your side calls for heat, it opens the passenger side valve.  if the passenger side gets hot and yours doesn't, it's the valve.  if your side still gets hot and the passenger side doesn't, it's the heater core.

THAT is a major job to change.