Reply to Thread

Post a reply to the thread: Where does my heat go??

Your Message

Click here to log in

Please correctly re-type the phrase f o o t d o c t o r in the form box. Re-type it without the extra spaces and put the one space where it should be. We apologize for having to do this but this silliness helps slow the spammers.


Additional Options


Topic Review (Newest First)

  • 01-29-2011, 04:14 PM
    Bob K.

    Maybe I finally got it!!

    Thanks for all the good inputs!! I cleaned the temp sensor during the summaer and it was indeed covered by dust. I have carefully followed the air bleeding procedure and I seem to have plenty of heat now. I've been here before so I'm not sure it is solved but it sure is better!!

    Has anyone had trouble with the radiator/fan shroud cracking where the resevoir attaches? I've been told it gets brittle and this is a common problem. My car has 110K and has only been used as a daily driver - though I can be a little spirited on the highway.
  • 01-23-2011, 08:25 PM
    Ed CT

    A couple of things to try...

    1. Vacuum out the temp "sniffer" vent louvre just to the right of the fan control button - it may be giving a false reading if no cabin air is being pulled into it due to it being clogged with dust.

    2. As many of us here are thinking, there's air in the system. With the engine cold, check the coolant level, top it off if nec. Drive to where you can park on a steep uphill (driveway, loading dock ramp, grassy knoll). Park with the front of the car raised, engine running, and heat on full hot. Stay here for 5 to 10 minutes, revving the engine once in a while. Next, drive home, park, open the bleed screw on the t-stat housing slowly, with a rag wrapped around the area, to relase any air trapped. Close it as soon as coolant flows from the screw. Don't over tighten the screw as it can crack.

    This will pretty much rule out having air in the system.
  • 01-23-2011, 05:39 PM

    When you bled it the last time, did you elevate>>

    the front end of the car?

    Jim Cash has posted here the correct bleeding procedure.
    Ed in San Jose. BMW CCA member since 1987 (Nr. 62319). Golden Gate Chapter. '97 540i 6 speed. Build Date 3/97. Aspensilber over Aubergine leather.
  • 01-23-2011, 04:59 PM
    Bob K.

    Re: If we knew the last 7 digits of your VIN we could(

    Well, I have verified the aux pump is working and will set about ensuring the system is thoroughly bled. The VIN is CK27408.
  • 01-23-2011, 04:46 PM

    If we knew the last 7 digits of your VIN we could(

    tell you more.
    I picked out a Jan '02 production date for the link below. This one has 2 pumps, the one under the solenoids you replace is #6. There is a aux pump also #2.

    You can also find most of this info if you put the last 7 digits of your VIN into the serial number box.

    If your engine is fully heated up and your heating system is OK you should feel very hot air coming from the vents under the dash.
    Forget about the 3 dot wheel, that just varies the temp of the air coming out of the top center vent.
    If you have hot air coming out of the vents and you manually turn the fan speed up to max do you continue to get hot air, or does the air temp start to get cooler?

    One other thing you could try is to unplug the connector for the 2 soleniod valves, #6. This will keep the valves open and allow hot coolant to continously flow to the cabin heater core. See if you get more heat when it's disconnected. The HVAC panel opens and closes these valves to regulate the temp. It's possible they are being kept closed for a longer period of time than normal by the HVAC panel.

  • 01-23-2011, 02:28 PM
    Bob K.

    A little more info...

    Thanks for the feedback. It is 27 F outside today and with the cabin temp pushed to 90 and three red dots on the top dial the fan is running at 50%. The air is warmer but this sort of setting should drive me out of the car when the engine is fully warmed up. Could it be the controller doesn't really know the temp in the car?

    What is the best way, if any, to determine if there are air pockets in the cooling system? Do all 2002 530i have the auxilliary heat pump? Is there a diagram showing where it is located?

    Thanks again for the help!!!
    Bob K.
  • 01-23-2011, 12:28 PM

    Have to agree with BMW540san, sounds like (m)

    you still have some air in the system, or possibly the small pump below the two solenoid valves you replaced is not running all the time.
    If you can reach the pump with the engine running you can feel if the motor is running, it pumps the coolant to the cabin heater core.
    The only other thing I think it could be (long shot) is the heater door flaps aren't working properly.
  • 01-23-2011, 12:27 AM
    Bob K.

    Re: Are you sure you don't have air pockets in your

    Well, you can never be sure with this car. I have bled it with no change in the condition. I have recently had the radiator replaced due to the traditional neck break and they also bled it. I also had a new resevoir put on by the dealer aroung 85,000 miles. This condition has been intermittant since the end of last winter.

    Bob K.
  • 01-23-2011, 12:08 AM

    Are you sure you don't have air pockets in your

    cooling system. It sure sound like the right symptoms.

    1998 BMW 540i 6 speed
    Arctic silver, M sport suspension (euro delivery), prod. date 05/98, non VANOS
    Staggered 18" style 32 OEM wheels
    3.15 open differential
    Remus exhaust
    AFE CAI with improved heat shield
    Z3 shifter
    VDO oil pressure and temperature gauges in place of headlight/fog switches
    Powder coated valve covers-satin black
    CDV delete
    AEA DRL module (aftermarket daytime running lights)

    1997 BMW 528iA
    Alpine white, premium package, prod. date 04/97, single VANOS
    Staggered 17" style 32 OEM wheels
    AEA DRL module
    Custom made sun blinds for rear seating area

    2000 Nissan Frontier Desert Runner, AKA "The Work Horse"

    Garage aids:
    Direct Lift Pro Park 8
    Campbell Hausfeld 28 gallon oil lubricated air compressor
    Newair ACP-1400H portable air conditioner and heater
    Auto Enginuity scan tool with BMW enhanced option
    Actron 9135 scan tool-for quick readouts

  • 01-22-2011, 11:48 PM
    Bob K.

    Where does my heat go??

    Hi all!!
    I haven't visited the forum for a while but my feet and nose have gotten colder than I can stand. I have a 2002, 530i with the automatic temperature control and 110,000 miles on it. Lately the heat has become erratic. I msy or may not get heat in the AM. As soon as the temperature gauge gets above the blue region the fan speed increases but the air in the footwell may not be very warm. On other occasions the heat is working fine and after an hour or more of driving it starts blowiong cold air (top and bottom). I can set the driver-side temperature to 90 and get a little warmer air - sometimes hot air but if I set it back to 72 it will be cold. I can advance the stratification control to 3 red dots with little change in top outlet temperature. Frequently, if I stop somewhere for coffee and then get back in the car there is plenty of heat until it decides to turn cold again.

    I have replaced the thermostat which was only getting to 80 degree C and now it is stable at 97 degrees. I have replaced the dual hot water heater control valves. I have cleaned the temp sensor in the IHKA control module - it was dust covered.

    Any ideas? All I have left is to replace the IHKA control module and I think the dealer has to program it if I replace it ($100?). I have also tried to eliminate any water in the system.

    Thanks for your help!!
    Bob K.

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
1e2 Forum