Lower part of windshield fogs up
Thread Starter
Senior Member
Joined: Feb 2003
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From: So. Cali
2002 CLK 430/2002 325i
Lower part of windshield fogs up
I have a 2002 CLK 430 with approximately 27K miles on it. The windshield fogs up at the lower part, near the vents, when the AC/Heater is in the off position. The fog appears only in two areas in the form of a 5" circle (one in front of the driver's side and the other near the center). The windshield fogs up, as described, after the car is coming to a stop. As the car begins to accelerate, the fog-like problem begins to disappear(keep in mind that the AC/Heater is turned off). It seems to appear when the car comes to a complete stop and after being in the stop position for several minutes the fog-like problem begins to go away. This problem is not evident whenever the AC/Heater is in the on position.
I have been to the dealer twice and the dealer has not been able to fix the problem....they informed me that there is nothing wrong with the vehicle. Has anyone experienced this problem or know what could be the cause??
Thanks in advance,
Ivan
I have been to the dealer twice and the dealer has not been able to fix the problem....they informed me that there is nothing wrong with the vehicle. Has anyone experienced this problem or know what could be the cause??
Thanks in advance,
Ivan
Super Member
Joined: Nov 2001
Posts: 864
Likes: 1
ML
I tend to agree with the dealer that there's nothing wrong with the vehicle. The condensation you see is a natural phenomenon and may not occur all the time depending on the weather conditions. If you have the windows up, then it will most likely occur all the time when the A/C is in OFF position - just from breathing and other evaporations in the vehicle. I believe late model MB vehicles (and other manufacturers) design new cars to turn on the compressor for a short while as your key engages the "ON" position. The reason for this is to have the A/C operate for a short period so that the condensation doesn't occur. Now, if you turn your A/C off, you'll have condensation. Notice that the manual says that the A/C system in AUTO mode is always ready. So just leave it in AUTO mode and set your desired temps.
The second reason the system should be on is to avoid fungi growth in the system. Depending on your ambient conditions, "things" (living organisms) may grow in there and cause a bad stench. Leaving it OFF is a catalyst for such growth. Leave it in AUTO and you'll have no problems.
The second reason the system should be on is to avoid fungi growth in the system. Depending on your ambient conditions, "things" (living organisms) may grow in there and cause a bad stench. Leaving it OFF is a catalyst for such growth. Leave it in AUTO and you'll have no problems.
Super Member
Joined: Nov 2001
Posts: 864
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ML
Originally posted by mdp c230k
Have them clean out the vents to remove the oily residue from the factory. It is this residue that causes the fog in may MB models. It fixed my problem with fogging.
Have them clean out the vents to remove the oily residue from the factory. It is this residue that causes the fog in may MB models. It fixed my problem with fogging.
Newbie
Joined: Apr 2003
Posts: 8
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From: S.F. CA
natural occurance
To prevent the fogging check to to see that the manual switch for the vent control is turned to the lower vents (down arrow). Some of the new 2003 cars automatically switch to the lower vent when the car is turned off to keep the windshield from fogging at startup.
Good luck
Good luck
