Condensation

[wayneC320]

Just thought i would ask the question, does anyone suffer from condensationproblems withtheir Merc? I have a 2000 C320 and i find that i get terrible condensation. It also takes a long time to clear. Does anyone have any suggestions i would be very intrested on how i could solve this problem.

Thanks,

 

[Geezer]

Have you got a leak? Check all your carpets, underneath preferably.

 

[wayneC320]

No, no leaks carpets are fine. all rubbers are in place that i have checked anyway. Even on a very cold day the dashboard displays are all steamed up. Have to drive the car for at least 10 minutes before i have decent visability.
The car also mists up very badly if i use the EC heating.

 

[st13phil]

This does not relate specifically to your Merc, but any car with a condensation problem. Unless you have a habit of getting in the car while soaking wet, or you keep a fish tank full of water on the back seat then it's safe to say that you have a water leak. All you can do is try to find the source and fix it.

Tips: Front or rear screen sealing is often the culprit, but it can also be caused by blocked heater, sunroof or door drains. Damaged door seals are another possibility and if the car's had a shunt in the rear then the boot seal is another candidate. Take any mats out of the car and feel for dampness of the carpets. If the condensation is very bad then the chances are that any sound deadening material under the carpet is waterlogged, so by pressing a finger firmly into the carpet you may force a damp patch to appear. If you can't feel any dampness from the top of the carpet you will have to start dismantling trim and lifting the carpet in your search.

Unless you're lucky in locating the source, prepare to spend some time tracking it down

 

[st13phil]

No, no leaks carpets are fine. all rubbers are in place that i have checked anyway. Even on a very cold day the dashboard displays are all steamed up. Have to drive the car for at least 10 minutes before i have decent visability.
The car also mists up very badly if i use the EC heating.

Two questions: 1) If you leave the car in sunshine with the windows rolled up does it get condensation on the inside of the screen/windows? If yes, then you have water in the car; 2) Is there "an aroma" in the car other than a smell of dampness? If so then it's possible that the heater matrix is weeping.

 

[wayneC320]

1. If i leave the car in sunshine with the windows up - it is fine no condensation can get in and drive away.

2. I do notice that there is an odd smell in the car other than condensation. Please can you let me know what the heating matrix is and is it expensive to fix?

Thanks.

 

[Blobcat]

Further to the above it maybe worth cleaning the glass and renewing the pollen filter it may be pretty badly blocked. I've never had a problem with condensation and find the AC does a great job of clearing the screen.

 

[st13phil]

1. If i leave the car in sunshine with the windows up - it is fine no condensation can get in and drive away.

2. I do notice that there is an odd smell in the car other than condensation. Please can you let me know what the heating matrix is and is it expensive to fix?

Your confidence that the carpets are dry and subsequent confirmation that the windows don't get condensation on them if the car's left in the sun certainly add weight to the notion that the car's not leaking.

The heater matrix is a a small radiator inside the heater assembly and is the heat exchanger through which air is drawn to provide heating in the car. I have no knowledge of the likely replacement cost on a Merc - somone else with more knowledge should be able to help on that. As far as the odd smell goes, whenever I've encountered a weeping heater matrix (not on Merc's, BTW) there was a sort of curry-like smell in the car.

Blobcat has made some good suggestions which are worth acting on. Also, try turning the heater off completely and closing the outlet vents. If you get in and drive around for a bit it will probaly suffer from some condensation due to your breath, but is it less than you get with the heater turned on?

 

[wayneC320]

Thank you both for your suggestions. I will try them out and let you know.

THANKS.

 

[Jensen]

I only find that when I'm in a que for a long period the front windscreen can mist up, with my breathe I think. I switch on the AC and it clears instantly.
The same with the rear windscreen but this mists up when people are in the rear. Clears when rear de mister is switched on.
Does this seem of any concern?

 

[jberks]

Do you keep the aircon on or off? From what you say, I assume off is the normal mode for you.
you're doing yourself no favours ever turning off the aircon. On a 320, the extra fuel usage is negligible and the side effects of running with it off are damp in the car (sound familiar?) and longer term, a failed aircon system as it must be used regularly to avoid the seals drying out and leaking. Also change the pollen filter.

Over time, especially in this weather, without aircon, damp can build up in the car - though yours does sound extreme. It will build up in the seats, carpets and sound proofing. Id also clean the windows thoroughly as any dirt (invisible or not) won't be helping.

I'd give this a couple of weeks and if it doesn't improve, start looking for leaks more closely. Mercs do fog up quite easily im my experince. MB seem to assume you keep the aircon on all year round. Not sure why but I do know I've turned mine off a couple of times and had the windows misting up within 1/2 an hour. I keep it on and it never fogs up.

 

[Speedmaster]

I had the same thing with my CLK430 and it was leaves blocked up the intakes at bottom of windscreen, causing water to leak into the car and the carpets got all soaked. Was a total nightmare and took ages to demist. Ended up renting commercial heaters and leaving it in the garage with them on to dry it out. Now always get garages to clear the vents when in for service