Condensation on interior windows 2015 SL400

[Red C220]

I know I've only had it just under 4 weeks and two of those I've been on ship - however first question on new SL ownership.

Is it normal to get condensation on the interior windows, particularly the rear and side windows?

It's most prevalent when I've been for a drive, the car has warmed up and is then cooling down - roof up all the time.

I'm not talking a little bit misty, quite a lot of condensation but not quite enough to ball up and run down the glass?

I don't have a garage and the car currently lives outside (but working on the possibility of garage this year).

I'm worried about this particularly with a porcelain interior.

 

[chrisdean]

Make sure you use your a/c, that's what it's for.

 

[Red C220]

Make sure you use your a/c, that's what it's for.

Yup I've made a conscious note to leave that on as it acts as a dehumidifier.

It's once the car cools down that the condensation starts to appear.

Is that what the "rest" function on the a/c is for, I can't find a mention in the manual

 

[richard]

Is that what the "rest" function on the a/c is for, I can't find a mention in the manual

Rest allows you to run the heating for a while with ignition off. It uses an extra pump to pump engine coolant around so the heating system can use it.

It allows you to park and turn the engine off whilst keeping heating go - and thus not pollute the local residents - such as outside a school waiting for the kids !

R

 

[Dec]

The A/C should be uses all year round, the A/C button should be light up, this will stop condensation.
The climate control should be set to Auto.

See page 146… http://www.mbusa.com/vcm/MB/DigitalAssets/pdfmb/ownersmanual/2014_SL.pdf
Or
Look for your cars manual here… Owners Manual: A Go-To Source for Information on your Vehicle | Mercedes-Benz

Dec

 

[StuartK]

Failing this try leaving a tray of cat litter in the car overnight it should soak the moisture up

 

[Red C220]

The A/C should be uses all year round, the A/C button should be light up, this will stop condensation.
The climate control should be set to Auto.

See page 146… http://www.mbusa.com/vcm/MB/DigitalAssets/pdfmb/ownersmanual/2014_SL.pdf
Or
Look for your cars manual here… Owners Manual: A Go-To Source for Information on your Vehicle | Mercedes-Benz

Dec

Yup doing both of the above. The issue isn't whilst using the car, it's perfectly clear. It's when it's parked up and cools down it fills with condensation.

 

[Sanke]

Search Amazon for a ThoMar car dehumidifier, far nicer than cat litter.

The wife's range is always damp inside due to moving mountain bikes, cross country running gear about in. This think definitely stops the condensation build up.

Steve

 

[markdt10]

Like you, I do not/cannot garage the car and I get exactly the same in my 2007 SL350,mostly on the inside rear screen in cold, damp conditions, - like the weather recently! It's just normal physics. Warm air inside the car condensing onto the cold glass with no airflow to move it away, exactly the same as at home in a single glazed house in winter when you turn the heating off at night ! Heating the car interior would solve it maybe....

 

[kid-jensen]

I'll bet if you feel around the floorpan, there'll be damp patches where water has got in...

Once the car has wormed up, it will start to evaporate, then condense on the cold windows..

Unfortunately sounds like you have a water leak...

If it smella a bit sweet when you're driviong, may be heater matrix leak.....you REALLY don't want that....

 

[C240Sport97]

try driving around with the windows down for about 10 minutes to air out the interior

 

[Deleted member 113659]

I'm sure Red isn't prepared to try some on these solutions given the purchase price of his new car. Cat litter? Car dehumidifier? Drive around for 10 minutes with window open?

PaulG sounds like he's onto something. Maybe a tiny leak somewhere. Have a good feel under both seats and around the carpet. Surely worth asking your dealer to check it out too.

Ant.

 

[C32Graham]

Having a similar issue with the GF's new Polo. Its 2 weeks old and every time you get in the car without fail the windows are all steamed up. Ok it clears in less than a few minutes but annoying all the same. My 13 year old C class doesnt do it!!

 

[Red C220]

I'll bet if you feel around the floorpan, there'll be damp patches where water has got in...

Once the car has wormed up, it will start to evaporate, then condense on the cold windows..

Unfortunately sounds like you have a water leak...

If it smella a bit sweet when you're driviong, may be heater matrix leak.....you REALLY don't want that....

It's brand new and bone dry. No evidence of leaks anywhere.

 

[Red C220]

try driving around with the windows down for about 10 minutes to air out the interior

I have a theory, I had a good read of the manual last night - the English version not the one in the links above.

The car condensates at night or when parked up after a journey but it generally clears by morning, so it's not what I think is a leak or serious issue.

I picked the car up on Christmas Eve and it's been chucking it down since. I have a feeling I've not driven the car on long enough journeys for it to warm up and completely aclimatise. Due to me being out of the country for the last fortnight it's managed to cover less than 300 miles in total so far.

If the weather's good this weekend we'll take it on a good long run (150-200 miles) and I'm hoping the dehumidifier part of the a/c dries out the atmosphere inside the car and levels things out.

Other than that we're potentially buying the house next door and combining it with our existing home which will give me plenty of room to put a garage up.

 

[C240Sport97]

Other than that we're potentially buying the house next door and combining it with our existing home which will give me plenty of room to put a garage up.

build a double garage at least

 

[Red C220]

build a double garage at least

I'd like to if we have the room.

 

[Red C220]

Update on the condensation issue.

Over the last three weeks I've been using the car regularly to get the first 1000 mile running in period complete, now at a little over 900 miles. Nearly there.

The condensation issues has reduced to a point that it's practically gone. The car clearly doesn't like sitting for extended periods without use, especially in damp weather.

I'm still working on a garage though, made the neighbours an offer and still actively looking for a new house with grounds/garaging. However house prices are absurd at the moment and I'm used to absurd house prices living in Surrey.

 

[Blinked]

I have a 12 year old SL. I recently had a big leak under the carpets which affected electrics etc ( that's another sorry)
After drying the carpets out and fixing the problem . I bought 4 moisture absorbing bags off eBay. Put two in the cabin behind the seats and two in the boot which is also prone to condensation. Must say they are working a treat. Recommended.

2x 1.5 kg DRY AIR CAR/HOME DEHUMIDIFIER BAG MOISTURE ABSORBER/RECHARGEABLE | eBay