'92 E36 notorious heater "no heat" problem

[JJohnsen88 9]

You probably came here knowing what I am about to say. Bought this car today on the drive home dad thought the heater blew warm/hot air. After stopping at home then getting back in testing the a/c if it worked by lowering temp right down and turning it on (turns out it doesn't seem to) then tested heat found out it didn't work and hasn't worked since. Read a few threads on here about why and it sounds like it's the Heater Control Valve...I have a $300 service manual but its black and white with obviously bad quality photos.

What I want to know is what are my likely options? Temp gauge needle sits nicely in the middle takes a while to heat up had it running on the spot for a while no oil drips but water marks around the edges of the car where it was sitting possibly from inside the body from when it was washed, both me and dad could smell a coolant type smell while driving he suggested it may have a cracked heater radiator hose or something like that (not familiar with heating systems as mine have always worked or never been a problem until now).

Edited June 3, 2013 by JJohnsen88

[antil33t 90]

Get a heater valve from a forum sponsor, but before that check to see if someone hasn't by-passed it in-case the heater radiator has failed.

[euroriffic 609]

Does it blow air at all? The "hedgehog" fan speed resistors are prone to failing aswell as the digital hvac control panel. If it does blow ( as good as your mum did lastnight ) check to see if the valve opens and closes first to make sure that works before going any further. If that all works could be blocked heatercore. Probably a good idea to overhaul cooling system while your at it. Cheap and easy enough on a m50

[JJohnsen88 9]

If it does blow ( as good as your mum did lastnight )

Ahh I see what you did there haha. Yeah it blows air just cold air all the time, but the odd thing is dad swears it was blowing warm air when I took it for a test run coz it had to demist the windows...in the time I sat at home before I went out again the car should have still been blowing hot air but no only ever so slightly warmer than outside air is at 5pm on a clear Winter evening, it wasn't on recirculate either and the aircon needs re-gassed too, it doesn't give out the crisp cool air that an a/c unit should.

Oh god I can see myself making a few threads in frustration at not being able to figure out problems

Edited June 4, 2013 by JJohnsen88

[Ahmedsinc 414]

Chances are your heater tap is jammed full of goo. There are plenty of how-tos on the net about removing and cleaning it out, just an awkward d*ck of a job. Cooling overhaul is advisable, these motors don't appreciate getting hot under the collar. Unless you have proof it's been done, assume it hasn't

[euroriffic 609]

Ahh I see what you did there haha.

Haha yea sorry, couldnt help myself!

Pretty sure the valve closes everytime you turn the car off so may be an intimitant fault as bmws are oh so good at if it was blowing hot on the test drive. But sounds like a sticky valve so I'd be making sure it opens or do it manually if you can. And as advised coolant system is a must if not done already. That includes waterpump and Tstat, not just coolant. And as said in your intro post, more than happy to help!

[Ahmedsinc 414]

And as advised coolant system is a must if not done already. That includes waterpump and Tstat, not just coolant.

Add a new radiator to that list too, as well as replacing any dying hoses. The end tanks on the E36s are know to blow from being brittle due to age. Might cost an extra $300 but better peace of mind than a dead car with you stranded.

Use BMW coolant too, the cheap crap ya get over the counter from local parts stores has a habit of rotting out the plastics in your cooling system. Costs about the same for the genuine stuff.

All stuff I learned the hard way

[euroriffic 609]

Yes should of mentioned radiator and hoses, my bad. And I found the BMW coolant cheaper than the "good stuff" and ripco and the likes too, and distilled water if your super fussy

[JJohnsen88 9]

Cheers guys but after reading this I kinda put it on the to do list as time goes by but a new discovery that has me scratching my head with only 1 possibility in mind. I get warm/semi hot air out of the front window demister vents but when I switch it to face vents I get blasted with cold air now to me that's saying the heater works just something isn't switching over properly. I haven't checked to see if I get warm air from the feet vents but for now let's assume I don't, what would be the likely culprit this time?

[euroriffic 609]

There's a separate dial under the center vents to change them from hot to cold, I bet it's on cold

[JJohnsen88 9]

Haha na I even switched that from hot to cold and back no change in temperature, warm air meanwhile still came out of the demister vent upon command

[BM WORLD 1283]

i sell plenty of heater valves , they all fail , sticky jammed up , perished seals etc

[JJohnsen88 9]

Quick update as of last night I can confirm I have warm air from the feet and demister just not face so my bet is that switch on the dash below centre vents is stuck on cold even though the tumbler moves freely left to right. Need to change headunits over anyway so might have a look behind the dash at the same time see if I can find this little stuck valve