[moldcad]

OK - this forum being so helpful I decided to post a request for advice on another little problem I'm having with my brand new M235i... But first, some intro if I may:

I have a small house with a single space garage in it; since it's my wife who does everyday shopping etc., in order to make life easier for her, I made the garage available for her car. My BMWs I keep in a stand-alone garage made of wood (it resembles a barn more than a proper garage, but who cares). With my F10, the first warm spring days I noticed this unpleasant smell from the A/C system... I was angry and complained on the quality of the car, as it was 2 months old then and during the 44 years of my having various car models (most of them with A/C), it was the first one actually smelling like this!

On March 14th this year, I put my brand new M235i in the same garage; it wasn't even 2 weeks before I started feeling the same smell each morning after starting the car! So now I know it's not the BMW's fault (the probability that two brand new BMWs in a row develop some fungi in their ventilation ducts in the first month of usage is too low to even consider, I hope). It must be lack of proper ventilation in this "garage" of mine - even though there is free air movement between the walls and the roof. I suspect it needs some opening(s) in the lower area of the walls to actually make the air circulate...

What do you guys think? I used to consider wood a very healthy, almost "self-breathing" material - but it looks like I was wrong. Do you agree with my little diagnosis here? Or do you think it's the car's fault, after all?

Thanks in advance for your opinion (and possibly some advise on DIY ways of the problem)!

[Sportstick]

To rule out one potential issue, you do run the HVAC system on AUTO rather than try to use it manually? The AUTO function includes a self-drying feature which prevents the growth of smelly mold. Once the problem starts, however, a trip to the dealer for ductwork cleaning is usually required to resolve. Over on the MB forum, from where I came last year, all who had this complaint about HVAC smell were those who tried to use their HVAC manually. There were no complaints from those who set it to AUTO and let it manage itself.

[moldcad]

Good question - the answer I should've included in the description of the problem. Of course the answer is: yes, I have the A/C button on at all times, without a single brake - also in the winter!

[3.0L]

My theory for preventing stinky A/C systems is to turn off the A/C about a mile before arriving at our destination. This technique has worked on our 3-year old MB GLK350, my 1-year old M235i and all of my previous cars. It's just a habit for me.

[Sportstick]

Originally Posted by moldcad

Good question - the answer I should've included in the description of the problem. Of course the answer is: yes, I have the A/C button on at all times, without a single brake - also in the winter!

Not trying to be difficult, but there is a difference from A/C to AUTO. Do you have the left round button engaged where it shows "AUTO", no matter what temperature you set? In the AUTO function, a drying cycle occurs to deal with the moisture generated by the use of the A/C. Sometimes, I realize you need to change for a MAX setting, for example, but AUTO should be engaged as much as possible.

[moldcad]

No, there is no misunderstanding between us - perhaps it's my English, but I do have both A/C ON and AUTO mode ON all the time.

PS From your questions I reckon you don't share my suspecting the garage with too little ventilation as the source of the problem, correct?

[moldcad]

May I bump this thread up, please, to get some second opinion on my main question: considering it's the second brand new BMW in the row that starts HVAC infection within the first month of usage, even though I have both A/C and Auto switches ON permanently - would you blame the humidity and high temperature in my garage for this?

As an additional info: with my 2002 E46 330i I used the same garage, and it never ever smelled from its HVAC ducts - even though, believe me or not, I never cleaned or disinfected the system; not even once (apart of course from replacing the cabin filters - but even this was done much less frequently than the books recommend). The car - even at the time when I was selling it back in 2012 - still maintained that BMW-ish scent of leather it had come with from the factory 10 years earlier...

[dtcoff]

I doubt that your garage would cause anything like this. Many of us live in much more tropical climates with high humidity the norm and all manufacturers run long term tests in varying climates around the world during development.

[moldcad]

Thanks - I'm tending to think the same, unfortunately. And I say 'unfortunately' because it isn't an indicator of good quality of BMW cars these days

Just FYI: the bad smell was never diagnosed (not to mention eliminated) in my F10 before I sold it into the current M235i! Yes, they applied some ultrasound germ killer and replaced the cabin microfilters - but all in vain...

[overcoil]

I do notice that the M235 HVAC heater generates good high temps - actually blistered my ankle running just bottom vent w/high blower speed - anyway I'm thinking running high HVAC heat periodically could be helpful?

[Cyberdemon]

Does the garage have the same odor without the car?

[moldcad]

No, of course not.