No heat when stopped at lights or in parking lots etc.

[mjbst111]

As long as I am driving, my car has wonderful heat (great temperature control)

If i stop at a red light long enough or if I’m sitting in a parking lot waiting for someone and just have my car turned on at idle, my heat turns into cold cold air as if i have turned off my car and left the fan on.

Anyone else see anything like this? I have the digital climate control. I cleaned the thermostat in the climate control and the tiny little fan is working.

And since we are talking about idle and all that I noticed that my car makes interesting clicking (or a quiet clunk maybe) noises from engine/dash maybe when I stop at red lights. This noise stops if I adjust the climate control temperature enough. I'm puzzled.

These things aren't terrible but it is an annoyance if anyone has any ideas I would very much appreciate it.

 

[andreyiv]

Could be air trapped in the cooling system, generally you get no heat at idle when there is air in the system.

 

[Kirby]

Could also be a stuck open thermostat, or a clogged heater core, or a bad heater control valve.

What is the engine temperature doing? Is the engine temperature normal and you get cold air? Or is the engine itself running cold?

If the engine temp is norma and coolant level is OK with no trapped air, then you need to look at the heater core and control valve.

 

[mjbst111]

Thanks so much for the replies.

I replaced the radiator a month or two ago... I didn't bleed it though cause i don't have a bently and assumed as long as it didn't overheat then there wasn't any trapped air. Do you think that what it is? The engine temperature is completely normal. It takes a normal time to heat up and stays straight up no matter what. No change in engine temperature ever. My buddy has a bently for a 94 325i, maybe my car is in there too....

hmmm. i've only heard that bleeding the coolant in an e36 is a pain, hopefully his book can give me some insight.

again, thank you so much!

(I really hope i don't have to replace the heater core....)

 

[Kirby]

There's a good chance that it is trapped air.

Assuming your year has the expansion tank, I think it does, the Bentley procedure is the same.

You can also read up on it at Pelican Parts:
http://www.pelicanparts.com/BMW/techarticles/E36-Coolant_Flush/E36-Coolant-Flush.htm

Tip - if possible, perform the bleed/fill on a slight hill with the front of the car uphill. This will ensure that the bleed point is the highest point of the system for air to rise to.

 

[mjbst111]

Thanks Kirby, very helpful...

I appreciate it!