Posted by Bob Hazelwood on September 24, 1998 at 09:40:00:
In Reply to: Re: HELP: Heater is not working posted by Anatoly Z. on September 23, 1998 at 10:37:01:
Below the solenoid valves you will find a small pump motor. You will need to
remove the entire solenoid valve/pumtp assembly to get at it. It's not
difficult, just remove the screws holding the assembly in place, and remove the
hoses going to the valves and pump. The wires will unplug. Once you have the
assembly out of the car, remove the pump from the bottom of the assembly. When
you see it, it will be obvious how it comes apart. You will notice that the pump
has two halves. The motor attaches to the impeller housing. You will have to
separate the two halves. When you do, you will notice that the impeller is
enclosed in its own watertight housing, and couples to the motor shaft through a
magnetic clutch. The buzz comes from the motor spinning Carefully pry the
plastic cover from inside the impeller housing so that you can remove the
impeller and shaft. Be careful not to damage the o-ring which seals the two
pieces. I bet you will find that the impeller is binding on the shaft. I think
that the plastic impeller somehow swells with age/heat so that it no longer
spins freely. I reamed the hole out with a drill until the impeller spins
freely, reassembled everything, and it's worked fine since. The whole thing
should take about 30 minutes to fix.
My dealer wanted to replace the valves for $200+. I like the free fix much
better. Just make sure you do it with the car cool, you'll spill a little
coolant during disassembly.
Anatoliy Zaytsev wrote:
: YES, It is exectly my case, I can hear the buzzing noise coming from the heater valve area.
: Please, advise me how to repaire this problem.
: Thank you so much.
: Best regards
: : : Please, help me figure out why the heater on my '90 BMW 535i is not working. When I turn on the rotary blower fan and temperature controls it blows the cold air.
: : : Thank a lot.
: : : Anatoly Z.
: : : '90 BMW 535i
: : Is there a buzzing sound coming from the area near the heater valves? I've known at least three E34 owners (including me) who found the auxiliary circulation pump became jammed. If this happens, you'll hear a buzz whenever the pump tries to operate. It can be repaired without requiring replacement.