Very Little Heat to Passenger Area

Post here for mechanical and engine topics such as fuel issues, transmission problems, rough idle, exhaust, electrical issues, etc

Moderators: GRNSHRK, ron, bfons

Post Reply
User avatar
BMWtyro
Posts: 320
Joined: Wed Oct 09, 2013 4:29 am
Location: Nebo, NC
Contact:

Very Little Heat to Passenger Area

Post by BMWtyro »

Our 8/84-built 633's heating system will barely warm the car.
The coolant level is correct.
The blower blows like a hurricane.
The heater control valve might be suspect EXCEPT that both heater core hoses are almost as warm as the rest of the coolant-carrying hoses.
A bit more defroster warm air is emitted than floor air, but they are both very weak compared to winters past.

Any suggestions?
Jeff & Dawn Dreibus
1984 633 CSi, 5-speed
1984 320i Baur, 5-speed
1987 325e, Automatic
GCR
Posts: 23
Joined: Tue Aug 27, 2019 12:08 pm
Location: Canton Ga

Re: Very Little Heat to Passenger Area

Post by GCR »

Always suspect the heater valve, if you're satisfied there are no air pockets in the cooling system. The valve is fully open without voltage applied, so a quick test would be to unplug the harness at the valve and see if you're getting heat. If you are not, then the valve is likely bad. It is possible that you have a restricted heater core, but I've never had to replace one due to restriction, only due to leaks. This is assuming of course, that your the thermostat is functioning correctly and the engine is not running too cool. Is the gauge in it's normal position?
Post Reply