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Greenfingers

Steaming up without aircon on

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Does anybody else find that during the winter months, their windows tend to mist up unless the aircon is on or a window left ajar?

I have heard about the F10 yellow grommet causing water ingress in the n/s/r footwell. My last E60 sunroof drains sometimes got blocked resulting in water in the boot, and my previous 7 series suffered from clogged front scuttles, which let water get into the front footwells, but I don't think this is the problem with my F07.

 

I can't actually find any evidence of water inside the car, so could it be something to do with a faulty EGR cooler (which I think is leaking) causing moist air to come into the cabin? Another thing I had with the E60, was the air recirculation valve failing into recirculation mode, but I think I can hear mine working. The A/C works fine, but if I leave it turned off on a cold and wet day, the windows steam up after a few minutes. I always have the fan running at least on low and as many vents open as possible.

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Just leave the aircon on. If the aircon clears the condensation quickly then I’d suggest it is merely moist air. A faulty egr cooler will leak coolant which will probably be consumed by the engine but it won’t find its way into the cabin. If it did you’d have the distinct coolant smell in the cabin too. 

 

It is good practice to run the aircon regularly if not all the time to keep the gas and oil circulating in the aircon system keeping the seals lubricated and the compressor in tip top condition. 

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Thanks for your reply, Matthew.

I do appreciate that is it good practice to run the A/C regularly to keep the seals lubricated, but surely we shouldn't need to keep it on all the time? After all, I ran a Vivaro van with no aircon for years and never had this problem.

The smell of glycol is distinctive, but might it not be so noticeable in small amounts? I remember the smell of a leaking heater matrix from years ago, but that was such a bad leak that the windows were literally dripping inside!

 

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25 minutes ago, Greenfingers said:

Thanks for your reply, Matthew.

I do appreciate that is it good practice to run the A/C regularly to keep the seals lubricated, but surely we shouldn't need to keep it on all the time? After all, I ran a Vivaro van with no aircon for years and never had this problem.

The smell of glycol is distinctive, but might it not be so noticeable in small amounts? I remember the smell of a leaking heater matrix from years ago, but that was such a bad leak that the windows were literally dripping inside!

 

 

I think you’d detect even a small trace of glycol if it was getting into the cabin but that’s not what the EGR faults lead to. 

 

If if you don’t have any noticeable water under carpets in the car I’d suggest there is nothing wrong. Our F45 has a propensity for steaming up when it’s cold outside and without the aircon on. 

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From memory of when the heater matrix died in my second Senator (pig of a job) the moisture is one thing, but what really gets you is how sticky it is in comparison to say sitting in a closed, cold car and breath 'huffing up' the windows.

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1 hour ago, HandyAndy_UK said:

From memory of when the heater matrix died in my second Senator (pig of a job) the moisture is one thing, but what really gets you is how sticky it is in comparison to say sitting in a closed, cold car and breath 'huffing up' the windows.

Yes, I think it's a horrible job on any car - due to inaccessibility and that sweet, sticky stuff.

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I think misting will happen in any car without air con looking back over the years at cars I have run without it.. Personally I run air con all the time. Better for the system and the climate control needs it to work properly in my view.

Edited by JCP

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Aircon on all the time when it's damp and raining or cold outside is only way to keep windows clear, unless you leave a window open a bit.

 You are the source of the moisture via your breath, your van might of been ok due to not being as sealed as a newer bmw is, I know from my personal experiences with older cars they don't suffer as badly due to having air drafts etc, or often a air system that allows air from outside in without the fan running.

 

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On 24/12/2018 at 16:13, Greenfingers said:

Does anybody else find that during the winter months, their windows tend to mist up unless the aircon is on or a window left ajar?

 

Yes that is normal in my experience, and given that my air-conditioning has stopped working, I'm experiencing it regularly now :(

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Can't comment on any BMWs in this respect but it's been an issue on most of the cars I've had to a greater or lesser degree. We currently have a 1999 vintage VW Passat and a 2007 Honda Civic. Both of these cars will mist up in cold weather. It's worse when there are more people in the car. A quick blast of the air con clears the windows and then I turn it off again.

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#yawn 

:rolleyes:

 

As others have stated that’s completely normal! 

Now im no air con expert, oh hold on..... ;) 

 

Im a bit shocked that a motoring giant at the forefront of motoring  engineering has not decided to make the A/C run all the time, unlike a smaller lesser known German company, Mercedes Bens or something it’s known by....

;) 

 

Come on peeps if you need to run your car with the A/C off then maybe you should think about downsizing/grading....

 

 

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