Do your headlamps look like this?!

[Michael 514]

Hi guys,
Thanks for all the input so far.
Yes, I know. It's been time to change dealers for a while. This Caddy dealer is three minutes from my house, though.
In any case, here is the TSB, and a note from the Chev dealer from where I bought the car. My salesguy is great, by the way. Super helpful.

Here:
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I have included a service bulletin for GM vehicles (including your 2008 CTS). They are correct....even if they replace the headlamp, the new one will likely have the same problem in times of high humidity. This condition is not caused by a water leak, but by high humidity. We often drill a tiny hole on the inside of the lens to release the humidity. GM would probably not approve, but it does solve the problem. If the problem persists even in times of low humidity, maybe there is a more serious problem (but I doubt it). It usually will not affect your visibility as the heat from the bulb will evaporate the water. Let me know what they say.

==============
#01-08-42-001G: Exterior Lamp Condensation and Replacement Guidelines - (May 4, 2009)
Subject:
Exterior Lamp Condensation and Replacement Guidelines
Models:
1993-2010 GM Passenger Cars and Trucks (including Saturn)
2003-2010 HUMMER H2
2006-2010 HUMMER H3
2005-2009 Saab 9-7X

________________________________________
This bulletin is being revised to add the 2010 model year. Please discard Corporate Bulletin Number 01-08-42-001F (Section 08 -- Body & Accessories).
________________________________________
The following information is being provided to better define the causes of condensation in exterior lamps and includes guidelines for determining the difference between a lamp with a normal atmospheric condition (condensation) and a lamp with a water leak.
Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions.
Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point


When this takes place, the moisture in the air within the lamp assembly condenses, creating a fine mist or white fog on the inside surface of the lamp lens.
Most exterior lamps on General Motors vehicles use a vented design and feature a replaceable bulb assembly. They are designed to remove any accumulated moisture vapor by expelling it through a vent system. The vent system operates at all times, however, it is most effective when the lamps are ON or when the vehicle is in motion. Depending on the size, shape and location of the lamp on the vehicle, and the atmospheric conditions occurring, the amount of time required to clear the lamp may vary from 2 to 6 hours.
Completely sealed headlamp assemblies (sealed beams) are still used on a limited number of models being manufactured today. These lamps require the replacement of the complete lamp assembly if a bulb filament burns out.

Condensation

2006 TrailBlazer Shown



A Fine Mist or White Fog on the Inside Surface of the Lamp Lens Occurring After a Period of High Humidity
• May be located primarily in the lens corners (near the vents) and SHOULD NOT cover more than half the lens surface.
• The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON.
• A comparison of the equivalent lamp on the opposing side of the vehicle indicates a SIMILAR performance.
If the above conditions are noted, the customer should be advised that replacement of a lamp assembly may not correct this condition.




Numerous & Various Size Drops of Water Collecting on the Inside Surface of the Lamp Lens After the Vehicle Has Been Exposed to Rain or a Car Washing Environment
• A condition that covers more than half the surface of the lamp lens.
• An accumulation of water in the bottom of the lamp assembly.
• A condition that WON'T clear when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON.
• A comparison of the equivalent lamp on the opposing side of the vehicle indicates a different performance.
Any of the above conditions would indicate the need to service the lens or lamp assembly.
========


Interesting......

[928S]

"I have included a service bulletin for GM vehicles (including your 2008 CTS). They are correct....even if they replace the headlamp, the new one will likely have the same problem in times of high humidity. This condition is not caused by a water leak, but by high humidity. We often drill a tiny hole on the inside of the lens to release the humidity. GM would probably not approve, but it does solve the problem. If the problem persists even in times of low humidity, maybe there is a more serious problem (but I doubt it). It usually will not affect your visibility as the heat from the bulb will evaporate the water. Let me know what they say."

Michael 514, the note from your salesman is dead on target. I have not asked my dealer to drill vent holes, as the occasional (high-humidity) condensation harmlessly comes and goes without leaving a trace.

[marktanner]

I can't believe that the humidity is worse in Montreal than it is in Atlanta at the peak of summer, or south Florida, where one's sunglasses will fog over. I've never seen this happen except when the seal has been broken, and usually on older cars. If this were truly normal, we should be seeing this all the time, but we don't. This would be unacceptable for me.

[Northern SRX]

Originally Posted by marktanner

I can't believe that the humidity is worse in Montreal than it is in Atlanta at the peak of summer, or south Florida, where one's sunglasses will fog over. I've never seen this happen except when the seal has been broken, and usually on older cars. If this were truly normal, we should be seeing this all the time, but we don't. This would be unacceptable for me.

I live in Ottawa (a couple of hours away from Montreal) and it gets quite humid here in the summers. 90%+ humidity isn't unusual at all. In fact, it's 90% out there right this minute.

That being said, I've been to Atlanta at the height of summer and have also been to the orient in the rainy season and Montreal's humidity is nothing like that - but those places lack the cool overnight temps that makes our dew such a treat...

Oddly, though, my CTS' lenses are crystal clear. Of course, it is garage-parked about 98% of the time it's not on the road.

[C "T" ess]

Here on the west coast of Florida, mine did this during the days of early spring when the overnight temps were lower than the daytime temps. As the bulletin says, they cleared up with in minutes once I drove the car even a short distance.

[2laidback]

It's a shame you put down your money and then to get fed BS afterwards. I've been through torrential down pours and my lights look like the day I got the car.Clean and clear!

[928S]

Michael 514, a couple of followup questions...

Is condensation (moisture) still visible on the inside of your headlight covers?

If not, did the condensation leave any visible (dry) residue?

[jelee01]

FWIW, I just acquired a '09 3.6L DI a few days ago. Mine also demonstrated similar conditions that Michael514 suggests, but like the service post mentioned earlier, the condition was identical across both lamps and cleared up following morning without any residual effect whatsoever.

[Michael 514]

Hi guys,
Thanks for all the posts.
The condensation does go away.
I don't see any residue...

The car is at the dealership right now, and I wasn't going to argue with the manager. He says it's normal, like the TSB, so I'll leave it for now and monitor it. Still over two years left on the warranty, so no panic!

[wfo]

Warranty

[C6Vette]

Hmm, sounds like what I said was right after all :-) Guys, you're over reacting to a very small problem that isn't going to cause any issues. It's not like the headlight is being flooded with water. This is a very small amount of condensation that forms on the lens, not the innards of the bulbs. As the bulletin says, as soon as it warms up the vapor evaporates. I wouldn't worry about it. My Vette has had it happen a few times now and it's 4 years old, no problem what so ever. Enjoy your car and don't worry about the little things that aren't important. I give myself an ulser every time I worry about something with the car, it's just not worth it.

[PAO]

agree with all above..it is NOT normal to have any condensation inside any lenses...regardless of the make or model....there is a definite fit/finish/seal issue involved here...

[928S]

Originally Posted by PAO

agree with all above..it is NOT normal to have any condensation inside any lenses...regardless of the make or model....there is a definite fit/finish/seal issue involved here...

GM Technical Service Bulletin, posted above by Michael 514, says:

"...Some exterior lamps, such as cornering, turn signal, backup, headlamps or tail lamps may exhibit very small droplets of water, a fine mist or white fog (condensation) on the inside of the lamp lens. This may be more noticeable on lamps with "multi-lens" designs and may be normal during certain weather conditions. Condensation occurs when the air inside the lamp assembly, through atmospheric changes, reaches the "dew point...The condition should clear of moisture when the vehicle is parked in a dry environment, or when the vehicle is driven with the lights ON..."

And, like C6Vette said, we're talking about occasional condensation (not a water leak) on the inside surface of the vented lamp assembly's outer lens (not inside the sealed lightbulb lens).

I'm with GM on this one.

[C "T" ess]

After you take a shower the mirror is covered in condensation which eventually evaporates. It's simply moisture that forms when two different temperatures meet. Just like in the headlamp. Once the temp is all cold or all hot (winter or summer) there will be no condensation. There will be no temp differential to cause it.
If you are still not convinced; call your builder to see if there is a TSB about leaking mirror seals.

[crystal_red]

I personally think all these multi-light enclosed fixtures should be vacuum sealed. No air = no condensation = no corrosion = no problems!