Author Topic: No Heat? (Read 13341 times)

roundel318 · « **Reply #30 on:** November 13, 2008, 02:06:20 PM »

water pump is new?
But are you sure its working correctly?

RED IS 91 · « **Reply #31 on:** November 13, 2008, 03:04:20 PM »

If the engine at idle does not stay around Half mark(temp gauge) but will stay at Half mark when traveling or higher rpms , I believe that would indicate a problem with the Thermostat. I know you say it's practically new but you've replaced everything but that so far.
good luck

roundel318 · « **Reply #32 on:** November 13, 2008, 03:11:48 PM »

I replaced my stat about a year ago and it was defective, doing exactly that. They popped another one in and it was good.
With the price of them, it might be worth snagging a spare :confused:

KenC · « **Reply #33 on:** November 13, 2008, 03:37:15 PM »

Quote from: RED IS 91;60652

If the engine at idle does not stay around Half mark(temp gauge) but will stay at Half mark when traveling or higher rpms , I believe that would indicate a problem with the Thermostat. I know you say it's practically new but you've replaced everything but that so far.
good luck

That's what I was thinking... esp after the drive I just took. The temperature fluxuated WAY too much for the thermostat to be functioning properly.

rthor234 · « **Reply #34 on:** November 29, 2008, 06:31:49 PM »

Sorry to bump a week or two old thread, but I'm currently dealing with the same issue.

I had no heat at all and the temp needle wasnt leaving the blue, so I went in after the thermostat. After replacing the thermostat the engine temperature comes up to mid-way and fluctuates. Appears to be better, but not perfect. I have heat when revving the car above 2500 rpm, but not at idle.

I'm wondering if the heater core bypass that was added in could be the culprit.. I'll go after that next.

Havent had any time to look deeper into it.

RED IS 91 · « **Reply #35 on:** November 30, 2008, 06:31:04 AM »

If a heater core by pass was done you wouldn't have any heat???
Make sure you bleed all the air out of the system ,Then bleed it again.
good luck

twright · « **Reply #36 on:** November 30, 2008, 04:50:04 PM »

The heater valve is a separate pipe connected to the heater core.

rthor234 · « **Reply #37 on:** November 30, 2008, 11:04:16 PM »

Quote from: RED IS 91;61956

If a heater core by pass was done you wouldn't have any heat???

Not sure why I said by-pass. I believe it's the pressure relief valve that was added in at the dealer to keep the heater core from bursting and covering the driver's feet.

I dont see how it could be an air bubble. I have never had a problem bleeding a BMW cooling system. But either way I'll be going into it again to see what the issue is.

KyleTaylor · « **Reply #38 on:** December 01, 2008, 02:54:10 PM »

Quote from: txleadfoot;59724

Mine had the opposite symptoms until I corrected the issue last night. The heater hoses at the firewall were reversed. I only got heat at idle and cold air while driving.

This is worth checking... I did this by mistake with my m50 swap a couple years ago and had temp flux issues and no heat unless I mashed on it and then the core exploded to boot!