Condensation Problems

Condensation Problems

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Ian B

Original Poster:

126 posts

271 months

Wednesday 4th January 2006
quotequote all
When the outside temperature gets below about 5degC I get big problems with condensation on the inside of the windows of my E320 (1998). Obviously this can happen to varying extents on any car, but it is really bad on mine for some reason. Eventually the windscreen and front side-windows clear (with the fan on and windscreen vents activated) but on some journeys, even over 20 miles, the rear side-windows and rear screen never clear. I've never had this with any other car, and there are no apparent leaks/damp carpets, etc.

Just wondered if anyone else had this problem and what can be done. I've tried all the supposed anti-mist sprays and wipes but they seem to make the problem worse. Also I never have the EC button pressed because the windows start to fog over at an alarming rate.

Thanks in advance for any suggestions.

Parrot of Doom

23,075 posts

241 months

Wednesday 4th January 2006
quotequote all
Does your coolant ever need topping up?

Also, I believe there is a vent at the back of the car near the parcel shelf on mine, perhaps yours is blocked/covered up?

>> Edited by Parrot of Doom on Wednesday 4th January 17:35

dazren

22,612 posts

268 months

Wednesday 4th January 2006
quotequote all
Maybe an aircon problem?

DAZ

justinp1

13,330 posts

237 months

Wednesday 4th January 2006
quotequote all
I have a similar problem on my 'new' '97 clk.

Even my TVR Tuscan with all the leaks and holes you could think of didnt mist as badly.

Parrot of Doom

23,075 posts

241 months

Wednesday 4th January 2006
quotequote all
Could also be the recirculate button stuck in the 'on' position (or whichever valve/flap it controls)

justinp1

13,330 posts

237 months

Wednesday 4th January 2006
quotequote all
Parrot of Doom said:
Could also be the recirculate button stuck in the 'on' position (or whichever valve/flap it controls)


Is that common?

My other thought was an aircon regas may help it work more efficiently?

I wonder though if it is just something about Mercs of that age? Even when I had a 92 Rover, obviously without aircon, the interior glass never got that misted.

Parrot of Doom

23,075 posts

241 months

Wednesday 4th January 2006
quotequote all
I can't see how the aircon being serviced would sort it out really.

When you drive a normal car with the recirculate button on, they get misty. Put the aircon on, and it stops getting misty. Turn the aircon off, misty again. Turn the recirculate and aircon off, and the mist goes.

Thats why I'm wondering if whatever flap is operated by the recirculate button is stuck in position so no fresh air is getting in. On some cars if you press the button you can hear the flap closing, and the air from the vents usually gets more powerful.


What model of Merc is it, chassis, engine, year?

>> Edited by Parrot of Doom on Wednesday 4th January 20:00

Ian B

Original Poster:

126 posts

271 months

Thursday 5th January 2006
quotequote all
Parrot of Doom said:


What model of Merc is it, chassis, engine, year?



Its an E320 with the V6 engine from 1998 (on an S Reg) if that helps.

I would be interested to know specifically where this vent is on my particular model, so that I can check if it is blocked. Anyone know?

Parrot of Doom

23,075 posts

241 months

Thursday 5th January 2006
quotequote all
Check:

Activated Charcoal filter, and cabin air filter (behind glovebox I believe, although they may be in the engine bay under the wiper)

Just a thought, if they are in the engine bay (I think mine is), the case might be leaking?

Ian B

Original Poster:

126 posts

271 months

Monday 13th February 2006
quotequote all
Parrot of Doom said:

Also, I believe there is a vent at the back of the car near the parcel shelf on mine, perhaps yours is blocked/covered up?


I found a vent in the boot (in the right-hand storage well) which I presume helps to draw air through the car. Mine was partially covered with maps and stuff which I’ve now moved into the left hand well. It seems to have helped a little bit, although that may just be because the weather has been milder this week.
Are there any other vents elsewhere? I would have expected to see something on the C pillar but there’s nothing.


steve-p

1,448 posts

289 months

Monday 13th February 2006
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I've got the same model and I've found condensation is sometimes a problem when the air temperature gets close to freezing when it has been a damp day. IIRC the manual says that the a/c doesn't operate below 3.5C, so it isn't drying the air. However, it's never a problem for journeys of more than 5 miles because all the glass has demisted by then, in any case. Perhaps you have moisture getting in somewhere in the cabin.