Heater Valve...

[1000_eyez]

Maybe this is not enough info...I don't know. Anyway, the hose from the heater valve to the firewall?...every few seconds it pulsates and makes a faint churp sound. Is this normal? Car is a 89 535i

[DueyT]

Yes, 1000, it is. The heater valve gets water from the engine block, passes it through an electric "auxiliary" pump (pumps heated coolant to the heater cores when the engine is idling), then feeds the heater cores (x2) through two electric solenoids. The solenoids cycle on and off to vary the amount of hot coolant flowing to each cabin zone's heater core. That churp sound and pulsating is the cycling of these solenoids.

Cheers,
Duey

[1000_eyez]

fast response, thanks! Glad to know it's normal Thanks for the info on how it works

[1000_eyez]

So today I was driving around and when I opened the hood, I always look under the hood to make sure nothing is out of the ordinary, checking oil...etc...Anyways, my when I opened the hood smoke was coming from the heater valve and was leaking. I took the cover off and tightend the six screws, the screws were kinda loose, cleaned the area up and drove some more. When I arrived at home I checked again, no leak!

[DueyT]

Yeah...I'm just waiting out on the heater auxiliary pump to come in from BMA...the one that the danged plastic impeller housing (to which the coolant feed from the engine water pump is attached ) broke...

Go figure that the one place that cheap plastic is used in a critical fail path on the car and I find it...ooops, wait a sec...the neck of the rads too...what is it with the cooling system?

Cheers,
Duey

[winfred]

also the thermostat housing, they split right on the seam on the v8s. brought to you be the same *******s that brought you the plastic m50 water pump, the cyclonic valve (pcv) on all motors built after 95 and some before, the windshield washer pump location on the e38/39.................. and many other fun annoying things

Go figure that the one place that cheap plastic is used in a critical fail path on the car and I find it...ooops, wait a sec...the neck of the rads too...what is it with the cooling system?

Cheers,
Duey