Results 1 to 13 of 13

Thread: Heater doesn't work

  1. #1
    Join Date
    Sep 2009
    Location
    Melbourne Victoria Austra
    Posts
    81
    My Cars
    E30 323i, E46 328Ci

    Heater doesn't work

    Well it works a little bit. When I first turn the fan on I'll get some heat but it doesn't last. Any thoughts where I should start before I get into it? I replaced the timing belt before driving it for the first time in the cold so can it have anything to do with the fact that I drained the coolant? Also, how hard is it to remove the heater core in these cars?

  2. #2
    Join Date
    Jan 2006
    Location
    Las Vegas
    Posts
    15,428
    My Cars
    00 E38,01 E38,99 323 is
    To bleed properly, you need to have the heat controls on full hot. Bleed the system with the bleed screw the highest point in the system. Bleed until there is no more air -- this may take more than one try.

    My best guess is that you did not bleed it properly, especially if it worked before your timing belt change.
    9/2004 Chevrolet Suburban Z71, black, purchased March 2016, 270k miles.
    6/99 740i Cosmos Schwartz M Sport, 214k miles, purchased May 2017
    2001 740i OrientBlau M Sport, purchased March 2023
    1984 MasterCraft Stars and Stripes, Blue/White, PCM Ford 351W, PowerSlot, 912 hours, purchased September 2012 (not a car )
    4/99 323is/5. Titansilber, 211k miles. Straight body project.



    past BMWs: 5/1994 325isa (Arktisgrau), 3/1997 328is/5 (cosmosschwartz), 9/1990 535i/5 (calypsorot), 9/1990 318i/5 (brillantrot) 7/93 325i/5 convertible (samoablau) 2/92 325i/5 cabriolet (lagunengruen).
    SÜNDE REISEN



  3. #3
    Join Date
    Nov 2006
    Location
    Tennessee
    Posts
    172
    My Cars
    89 325i, 87 325is, 91 525i
    Where is your temp gauge pointer during this? If way low I suspect your thermostat is broken open. If way high, agree with Strad.

  4. #4
    Join Date
    Sep 2009
    Location
    Melbourne Victoria Austra
    Posts
    81
    My Cars
    E30 323i, E46 328Ci
    I don't know if the heater worked before the timing belt change. I drove the car home on a warm day and replaced the belt as the first job (car came with no history). I'll try bleeding it again with the nose raised.

    Temp shows about half way.

  5. #5
    Join Date
    Jan 2006
    Location
    Las Vegas
    Posts
    15,428
    My Cars
    00 E38,01 E38,99 323 is
    About half way is correct for a standard thermostat. Just make sure you have the heat controls on full hot -- otherwise the heater core won't bleed.
    9/2004 Chevrolet Suburban Z71, black, purchased March 2016, 270k miles.
    6/99 740i Cosmos Schwartz M Sport, 214k miles, purchased May 2017
    2001 740i OrientBlau M Sport, purchased March 2023
    1984 MasterCraft Stars and Stripes, Blue/White, PCM Ford 351W, PowerSlot, 912 hours, purchased September 2012 (not a car )
    4/99 323is/5. Titansilber, 211k miles. Straight body project.



    past BMWs: 5/1994 325isa (Arktisgrau), 3/1997 328is/5 (cosmosschwartz), 9/1990 535i/5 (calypsorot), 9/1990 318i/5 (brillantrot) 7/93 325i/5 convertible (samoablau) 2/92 325i/5 cabriolet (lagunengruen).
    SÜNDE REISEN



  6. #6
    Join Date
    Jun 2006
    Location
    Peterborough, ON, CA
    Posts
    250
    My Cars
    '89 325ix, '88 325ix
    verify the hoses going to your heater core are on correct. they get mixed up all the time and causes poor flow and radiation.
    325IX:
    88 4 door 5sp DS:89 4 door auto AWII:88 TOURING 5 spd DS

  7. #7
    Join Date
    Sep 2009
    Location
    Melbourne Victoria Austra
    Posts
    81
    My Cars
    E30 323i, E46 328Ci
    Cooling system has been re-bled with heater on full and still got no heat.

    So I then turned the heat control back and forth to see if there was any difference between full cold and full hot and then for no apparent reason, some real heat started to come out with control on full hot. I then gave the engine a bit of a rev and lotsa heat came out. I then turned the heat control slightly to cool and lost nearly ALL the heat. So then I turned the heat control to full again and got nothing... well a little bit more than cold, but not much. So I tried to repeat the whole process again but nothing doing... still cold.

    So what on earth is going on?

    A couple of extra bits of info. Before the heater came good, the "in" hose was hot but the "out" hose was cold. After the heater stopped working, the car stalled and I couldn't get the car to idle. I don't think the idle thing is related but I thought I'd throw it out there just in case it does mean something.
    Last edited by lemans; 06-12-2010 at 03:13 AM.

  8. #8
    Join Date
    Mar 2007
    Location
    St. Louis mo
    Posts
    157
    My Cars
    325
    there's a electrical valve that opens and closes as you turn on the heat.
    It sits on the inlet side of the heater core under the dash.
    You should feel it click as you turn the heater on and off, the engine won't need to be on but the key does

  9. #9
    Join Date
    Sep 2009
    Location
    Melbourne Victoria Austra
    Posts
    81
    My Cars
    E30 323i, E46 328Ci
    Quote Originally Posted by subdewd View Post
    there's a electrical valve that opens and closes as you turn on the heat.
    It sits on the inlet side of the heater core under the dash.
    You should feel it click as you turn the heater on and off, the engine won't need to be on but the key does
    Thanks, that's a good hint. Too late in the evening for me to try it now but, by "feel" do you mean "hear" or do I need to put my finger on it to feel it? At what point in the turn should it click?

  10. #10
    Join Date
    Mar 2010
    Location
    CALIFORNIA
    Posts
    787
    My Cars
    1986 325ES STICK
    Revving it up and the heater got warmer? Me thinks theres still air in the system. classic symptom of air and/or low coolant.

  11. #11
    Join Date
    Sep 2009
    Location
    Melbourne Victoria Austra
    Posts
    81
    My Cars
    E30 323i, E46 328Ci
    Quote Originally Posted by grantorino62 View Post
    Revving it up and the heater got warmer? Me thinks theres still air in the system. classic symptom of air and/or low coolant.
    So is there some reason why it won't bleed properly? Are there any ways of knowing for sure that its a bleed problem?

    PS. I bled it according to strad's method. And just to be extra sure I let the coolant stream out for at least a minute after the engine heated up to normal running temp... and I kept the revs up to 2000rpm (while all the time topping up the coolant).

    PPS. I've noticed on the wiring diagram that the AC ha some sort of cutoff switch when the AC gas pressure is low. I have no gas in my AC at the moment. Could this have anything to do with it?

    PPPS. The "boss" has banned me from doing any major work on the car this weekend cos she needs to use it but any help still accepted in readiness for when I get around to it.
    Last edited by lemans; 06-13-2010 at 10:02 AM.

  12. #12
    richardodn's Avatar
    richardodn is offline Old Guy BMW CCA Member
    Moderator
    Join Date
    Nov 2008
    Location
    Lakewood, CO
    Posts
    9,942
    My Cars
    20 440ix cab, 12 X3 35ix
    The cut off switch is for the AC compressor. It has no effect on the heat. The heater valve should open by a 1/4 from full cold.
    "Howdy, Folks!"

    1986 Delphin 528e - Roof rack equipped lumber hauler.
    1989 Zinnoberrot 325iX Sedan - I miss this car. (Deceased)
    1998 Avus Blau 328iC - Someone else's project now
    2008 Platinum-Beige X3 3.0si - Current project
    2012 Alpine White X3 xDrive35i - My new snowmobile.
    2020 Estoril Blue 440i xDrive cabrio - This car is a blast to drive.

  13. #13
    Join Date
    Sep 2006
    Location
    Los Gatos CA
    Posts
    4,246
    My Cars
    1987 325is, e34, Z3, e39
    Also check the hose routing: the hot hose from the back of the head goes to the lower tube. The cool outlet returns to the thermostat housing. The flow must go *up* to bleed air bubbles.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •