85 528e - BMW Forum

gambino · 07-04-2004, 10:23 PM

I have a 85 528e, 85000 miles runs great. But anytime i turn the airconditioner on the cold air blows air through the front regular vents, and then there is heat which comes through the defrost vents, and the floor vents at the same time.I know this should not be happening. Any help or info given will be greatly appreciated.

Thanks

warp1 · 07-06-2004, 10:42 AM

Dead heater control valve. Hangs on the middle of the front of the firewall. Two ~1" coolant hoses and one electrical connector going to it. You can replace the core with a $30 Bosch part whose # I don't recall. BMW doesn't sell them except as a complete ($$) unit, but Benz, among others does. It's a drop-in part.

Biggest problem may be getting those four damn little screws out. The sage advice is, when you do, replace them with phillips heads or bolts.

E28boi · 07-07-2004, 09:32 PM

I don't believe the heater valve is the problem.
Whenever you turn on your a/c, there is a flap in the heater box that closes and stops fresh air from entering the car(recirc. mode). This flap is electric and is probably malfunctioning.