Cabin heater not producing hot air

Tiny
DENSAILS
  • MEMBER
  • 2004 BMW 530I
  • 3.0L
  • 6 CYL
  • RWD
  • AUTOMATIC
  • 81,000 MILES
My heater is not working properly in my car. I have some heat but its very little. I can have the heat turn on high and can hear it but when I out my hands next to the vents, I can feel very little or no air at all. Once I have driven it for 30mins, its a little warmer but never full air coming out of the vents. It always sounds like the window defroster is on and it receives more power and heat but never the full capacity.
Wednesday, January 1st, 2014 AT 10:39 AM

5 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Is the problem that the heat is not hot or is it there is little air flow from the vents? Is it coming out the defroster with full power?
Was this
answer
helpful?
Yes
No
Wednesday, January 1st, 2014 AT 6:08 PM
Tiny
DENSAILS
  • MEMBER
  • 3 POSTS
Air comes out of the foot wells but is barely warm never hot. The air from any of the vents and defroster is not "hot". Engine coolant is full and no leaks. Thanks.
Was this
answer
helpful?
Yes
No
Thursday, January 2nd, 2014 AT 2:22 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Okay, that leaves only a couple issues that can cause this. First, I need you to start the engine and allow it to warm up to normal operating temp. (You can do this after a trip too). With the heater on high, I need you to feel both heater core hoses. Both should be very hot to the touch. If only one is hot and the other warm, chances are the heater core is partially plugged. If both are hot, then I suspect the blend air door is not opening properly and allowing the heat to enter the vehicle.

Check that and let me know what you find.
Was this
answer
helpful?
Yes
No
Thursday, January 2nd, 2014 AT 2:46 PM
Tiny
DENSAILS
  • MEMBER
  • 3 POSTS
Heater core hoses are both hot. How can I access the mixing doors. Is the problem likely an open vacuum line or the dash controls or a fuse somewhere?
Was this
answer
helpful?
Yes
No
Tuesday, January 7th, 2014 AT 7:49 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
It could be a broken line or bad actuator. The door is located near the heater core in the heater core box. Not easy to get to.
Was this
answer
helpful?
Yes
No
Wednesday, January 8th, 2014 AT 7:19 AM

Please login or register to post a reply.

Related Heater Not Working Content

Heater Not Working
VIDEO
Heater Not Working
Instructional repair video
Heater Not Working
GUIDE
Heater Not Working
Step 1 - A heater cannot operate unless the engine is full of coolant/antifreeze. If coolant level is low check the system for leaks.