blend door question
 

2001 3.0 with the basic 3 knob a/c controls.


is the main blend door vacuum operated?


past two days when I'm at a stop, I lose all heat. once I start driving it comes back so I'm thinking the blend door (if vacuum operated) must be starting to fail (probably internal diaphram). does this sound about right?

Here's just one (FUB) explanation of the IHKR system used on the e53/e46/e39 semi-automatic system (that uses the dials and bowden cables): https://www.newtis.info/tisv2/a/en/e...bution/X8tx6rN



And connecting pin X611 (on back of the IHKR)...pins #7, #8, #9, #10 operate the fresh air flaps...which would indicate that the flaps are electronically actuated:

ok, so that eliminates vacuum as a possibility. hmm. I wonder why its doing this at idle then since its electronically controlled. time to start searching.

I have this old info (below) that was specifically for the e38 with the IHKA (fully automatic) system. But since the e38/e39/e53 share many design commonalities...although this is for an upgraded system...the fresh air flaps probably still have some type of set-up to compensate for more air coming into the system the faster you go which would mitigate the ram air affect. The IHKR systems in the e39 & e53 may not vary the "blower speed" but I bet there's something affecting the position of the fresh air flaps based on speed. What that would be, I don't know (yet). :)


FYI:

That sounds like low anti-freeze, head gasket, water pump.

I dont know why it didnt dawn on me to check the coolant, yup! its definitely low.



any special type I need to use or can I just get the standard green stuff from the parts store pre-diluted?

I just grabbed some prestone for european cars. took almost all of it. now I have heat again. now to figure out if I have some sort of slow leak or whatnot.

Love the easy fixes! :thumbup:

An often overlooked slow leak is the temp sender on the lower rad hose.

Yep, that one was leaking on mine a year ago. I replaced the entire hose with sensor.