Re: Noise from behind dash vents in E36

> I have the same noise.  It is sort of a rhythmic thud, which you can really
> hear when sitting at a stop light.  The dealer told me that it has something to
> do with a valve or pump located on or near the fire wall for the hot coolant
> that is pumped through the heater core for the automatic temperature control
> heating/A/C system.  Indeed if the HVAC system is turned off the noise doesn't
> occur.
> He said that a lot of BMW's do it, some are noiser than others, I've always
> just lived with the noise because I've become so annoyed with the poor service
> I got from the service manager that I was tired of complaining. I'm taking the
> car to a different dealer the next time I need something done perhaps I can ask
> them to fix it. Has anyone else out there had this problem and what was the
> dealer fix.
I have it too in a '92 325i. I showed it to the dealer (Afzal may be
interested to know that it was Pius Buchs in Geneva) and got a similar
explanation. Except that I don't have the A/C. It's supposed to be a valve
that regulates coolant circulation. I don't hear it when the engine is 
cold. With a warm engine at idle it makes rhythmic thumps with a few
seconds intervals. There was no fix.

> > the central vents in the dash of my 94 318is. Each time I hear the
> > noise, I also feel a slight pulsing in the breaks. The noise is normally
If it is the same phenomenon, you are just feeling the thud through the
brake pedal. Otherwise it is not related.