Re: My car does this: (archive)

Well, sounds like you have the classic E34 heater core coolant leak. This seems to be a common problem with either the plastic inlet pipes or the seals to the heater core. Much discussion on this in the archives. This would account for your sweet smell and fogging of the glass.

Not certain about your center vent issue. Can't really tell from the writeup if you have a problem or not. Check the archives here too (search on center vent). There is a lot of discussion about the stepper motor coming loose from it's clips. Sounds like a relatively easy repair.

Jeff
90 535iM

: A year ago everything worked perfectly in my 1990 535iM. Now the HVAC is on the fritz! Here's what my car did, and what it does now:

: THEN (when it worked)

: - I could change the left and right temps by independently turning the climate control temp KNOBS on the dash (under the stereo). The temp change was noticieable in dash vents as well as footwells.

: - I could change just the DASH vent temps (the 2 vents in the center and the 2 by the side mirrors) globally with the thumbwheel, but the footwell temp was NEVER affected. Left and right temp differential WAS maintained (by knobs under stereo) no matter what thumbwheel setting was.

: - 2 small vents in center console for rear passengers NEVER changed temp with any knobs or thumbwheel adjustment, but footwell temps would change slightly with left/right knobs

:
: WHAT HAPPENS NOW:(on the fritz)

: - I get hot air out of either the left or right center vents, especially when the A/C is cycling (doesn't happen as often when just venting fresh air). This is usually accompanied by a sweet coolant smell. Not enough to overwhelm you, but just enough to notice. *** Note: I notice that when the car is blowing hot air, it is no longer venting de-humidified air (as if the A/C was cycled off or broken). The hot air usually smells of coolant and is very moist (often fogging up windshield for a moment).

: - If I turn the left knob all the way COLD, it truly overrides both left and right temp settings (as described in manual for defrost settings?) and both vents will blow cold air. As soon as I return the knob to its normal position, hot air will blow out of one of the center vents again.

: - Now when I turn the thumbwheel, it seems to react after a delay, and I hear some flaps or doors moving somewhere inside the dash.

Follow Ups:

Thanks, I'll check into those items... (eom) Ben 06:17 4/11/2000 (0)

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