C-Class Exterior Windshield Fogging
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C-Class Exterior Windshield Fogging
Has anybody had a problem with exterior windshield fogging in the the area above the center vent ? This only occurs with A/C on humid days. I know there is a grille replacement but I don't see how that could affect the exterior fogging that occurs. A quick wipe from the windshield wipers solves the problem but it looks pretty strange when you have this triangular fog appearing in the center of the windshield.
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1994 Chevrolet Lumina
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I have observed this as well, I was test driving a coupe on Friday and it was doing that constantly, I meant to ask the dealer what was up with that but I forgot. I didnt actually notice if it was on the inside or outside though.
Patrick
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2001 C240/2000 ML320
There is a tech bulletin regarding replacing the center grill - pn 203 830 1118 due to window fogging.
Oops, never mind, I see you state it is exterior fogging.
Oops, never mind, I see you state it is exterior fogging.
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2002 C230 K
Originally posted by Fuzzo
isn't htis normal if you have the AC on and if it's hot outside.. why is this strange...
isn't htis normal if you have the AC on and if it's hot outside.. why is this strange...
Cheers, BT
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There is a grille replacement for some reason as mentioned by rskinner. Does anybody know what this is for ? If the fogging was on the inside I could see why a grille change might work but the fogging is clearly on the outside. If the new grille is still perforated I don't see how this could change anything.
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#9
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Originally posted by Lynn
The new grille is the reduce interior fogging due to outgassing of the plastics in the grille. I suppose the new grille uses different plastic.
The new grille is the reduce interior fogging due to outgassing of the plastics in the grille. I suppose the new grille uses different plastic.
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Originally posted by Lynn
The new grille is the reduce interior fogging due to outgassing of the plastics in the grille. I suppose the new grille uses different plastic.
The new grille is the reduce interior fogging due to outgassing of the plastics in the grille. I suppose the new grille uses different plastic.
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Originally posted by rskinner
Do a search for "W203 C-Class tech bulletins" and the fogging issue was covered there by mbtech208.
Do a search for "W203 C-Class tech bulletins" and the fogging issue was covered there by mbtech208.
Not really. It can only be assumed that the grille issue ONLY solves the problem if you have INTERIOR fogging. No mention is made of EXTERIOR fogging. The real question is does that new grille reduce exterior fogging also ? It could quite possibly deflect the air stream so that the window does not get cold. Unless MBtech208 answers this we will never know what the bulletin really addressed.
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Last edited by viper; 05-29-2002 at 05:05 PM.
#13
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The center of the windshield fogs due to a residue released from the center vent, whether it is the vent or something else in it I dont know. The tech bullitin says to replace the vent to get rid of the problem. It is on my list of stuff for the first service visit.
#14
Re: C-Class Exterior Windshield Fogging
Originally posted by viper
Has anybody had a problem with exterior windshield fogging in the the area above the center vent ? This only occurs with A/C on humid days. I know there is a grille replacement but I don't see how that could affect the exterior fogging that occurs. A quick wipe from the windshield wipers solves the problem but it looks pretty strange when you have this triangular fog appearing in the center of the windshield.
Has anybody had a problem with exterior windshield fogging in the the area above the center vent ? This only occurs with A/C on humid days. I know there is a grille replacement but I don't see how that could affect the exterior fogging that occurs. A quick wipe from the windshield wipers solves the problem but it looks pretty strange when you have this triangular fog appearing in the center of the windshield.
#15
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My car did this as well when I had it on "Auto". I switched over to manual and selected half-way between the floor and the dash on both sides. The fan is still on "Auto". No more fogging.
#16
Is this really a "problem?" I've driven several cars whose windshields condense moisture on the outside from the standard defrosting vents. All that's required is a good A/C defroster driven in a very humid climate.
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Originally posted by MB-BOB
Is this really a "problem?" I've driven several cars whose windshields condense moisture on the outside from the standard defrosting vents. All that's required is a good A/C defroster driven in a very humid climate.
Is this really a "problem?" I've driven several cars whose windshields condense moisture on the outside from the standard defrosting vents. All that's required is a good A/C defroster driven in a very humid climate.
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2002 C240 6-spd (ret)
I've read this thread pretty quickly, but I think there is no problem. I have my center vent pretty much closed (upper dash vent), but I get some condensation above the normal defrost vents when it's very humid outside and the A/C is on. Some amount of air is directed to the defrost vents during normal operation, and it's just a law of physics that water will condense on a cold surface. I don't think this has anything to do with vent position, etc. It's simply the cold air blowing on the windshield. Just tap your wiper to mist for one cycle and it goes away. Like someone else suggested, try closing your center upper dash vent during these conditions to minimize the problem. Just my $.03!
#19
Originally posted by viper
No its not really a problem. But I am sure we would all like to know why they issued a new part for this. Or was the new part with reference to some other problem. As I said before nobody really knows what the tech bulletin addresses - inside or outside fogging. MBTech208 where are you ? Can you print the specifics from the bulletin ?
No its not really a problem. But I am sure we would all like to know why they issued a new part for this. Or was the new part with reference to some other problem. As I said before nobody really knows what the tech bulletin addresses - inside or outside fogging. MBTech208 where are you ? Can you print the specifics from the bulletin ?
This was a temporary problem in my sedan, which I solved (pre-bulletin) by leaving the vent open through the Summer and letting the hot Texas Sun bake the solvents out of the plastic pieces... Clean the inner windshield when the "outgassing film" gets too objectionable, once weekly initially but every 2nd or third week toward the end of a 3-4 month period. BTW, the outgassing film also settles on the inner surface of your sunroof glass (if equipped), but is much less noticeable.
I had a similar problem in an early model Honda Accord that persisted the entire 7 years I owned that car, so this, by comparison is no biggie. And no, I haven't seen the actual service bulletin... just know there is one.
The OUTSIDE condensation issue is completely different, and I'm not aware of any service advisory for this common A/C problem, which can be addressed as Revstriker describes above... the catch-22 is that if you close the vent to stop occasional condensation on the outside, the solvents on the inside remain trapped below the dashtop vent.
Hopefully this clears up the confusion. Whew!
Last edited by MB-BOB; 05-30-2002 at 08:13 PM.
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Thanks MR-BOB.
On the coupe however the triangular perforated grille is all metal even though the underlying parts in the dash may be plastic. Maybe on the C240 and C320 the grille is plastic.
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On the coupe however the triangular perforated grille is all metal even though the underlying parts in the dash may be plastic. Maybe on the C240 and C320 the grille is plastic.
#21
Originally posted by viper
Thanks MR-BOB.
On the coupe however the triangular perforated grille is all metal even though the underlying parts in the dash may be plastic. Maybe on the C240 and C320 the grille is plastic.
Thanks MR-BOB.
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On the coupe however the triangular perforated grille is all metal even though the underlying parts in the dash may be plastic. Maybe on the C240 and C320 the grille is plastic.
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2002 C230 K
Originally posted by MB-BOB
I had a similar problem in an early model Honda Accord that persisted the entire 7 years I owned that car, so this, by comparison is no biggie.
I had a similar problem in an early model Honda Accord that persisted the entire 7 years I owned that car, so this, by comparison is no biggie.
Of course, I imagine within a week after it stops the entire dashboard will crack like a crystal wine glass when Eliza hits a high-note.
Cheers, BT
#23
Originally posted by Lynn
Interesting, because my grille is not all metal.
Interesting, because my grille is not all metal.
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I do remember someone's summation of the hazing problem as coming from the mesh below the grille... Metal doesn't have a solvent leaching out of it.
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