camcamaro1991

iTrader: (19)

Guys I just wanted to report back on this thread, I live in TX and the past few months we have had some crazy rain, its been humid as .... well just like Houston IMO, lol. So I have actually had to run my A/C for defrost reasons, anyways theres a slight A/C odor from time to time but its noticeably less, mother nature always wins in the end.

Tip 1
For those who already have bad odor, make sure you clean your heater core and A/C evaporator really good before you install a filter, or during a filter change. Last I remember from my Mercedes Benz tech days (the odor still haunts me) the odor is caused by bacteria growth due to the left over moisture from the a/c evaporator, the carbon filter helps reduce bacteria transfer, from outside air to the case, but as we all know air and bacteria free to travel down the vents to the case, even so when then fan is off so its a moot point, I leave my fan on 2-3 bars of fan speed to keep clean filtered air flowing out the vents but this only helps when driving and the truck is running.

Tip 2
Make sure you run your fan on high A/C OFF & recirculate OFF, about 2 mins before you get home to help dry out the evaporator and case, reducing moisture in the case reduces the odor (note: some/most home A/C's do this automatically, after the compressor turns off, the fan will run at a lower speed to dry EVAP to reduce moisture)

Tip 3
By installing a A/C cabin filter it helps keep the EVAP clear and clean from debris, so forth it helps reduce blockage of the A/C water drains from dust, leaves, straw, etc...., again from above reducing moisture to limit bacteria growth. With this carbon filter install and the tips I listed, there is a noticeable reduction in odor.

Thanks

miller white

iTrader: (2)

Is there any benefit to adding the filter really?

KC_kid

iTrader: (5)

Functionally there is a benefit to protect your evaporator coil from getting clogged with debris and decreasing efficiency. I would also say that breathing filtered air is always better than unfiltered air. I suppose it's up to you if the benefits are worth the cost and time to install. If you have a 2004 then you have a factory installed air filter.

KC_kid

iTrader: (5)

I could be wrong on this. My 2001 had a cabin filter but I see now the post applies to 2003+ GMT 800

BigBlueLB756

Put in a carbon filter today.
Good mod.

Atomic

iTrader: (42)

I did this to my 04 several years ago. It helped keep dust down in the truck, but there was an obvious pressure loss from the fan (didnt blow nearly as hard).

camcamaro1991

iTrader: (19)

Atomic,

the newer GMT900's have much higher output from the fan and slightly better designed HVAC case, I only noticed a very little slight drop in loss output, compared to the GMT800's which would suffer, as I have had both trucks chassis.

Ken in AZ

My 2002 has a pair of filters in it already. I bought the truck and noticed the AC was only trickling out of the vents, so I crawled up under there and pulled them out and they were nearly clogged. Blew them out with an airhose and reinstalled and AC blows much better.

So, did someone do this mod to my truck before I got it, or is this to mod the already there filters? I'm confused.

thanks!

camcamaro1991

iTrader: (19)

GM installed them up until 2003 I believe, but in 2004-2013 they needed a retro fit.

2014+ get factory filters, its behind the glove box, much better design as its ahead the fan instead of behind it, meaning no leaves/debris in the fan assy...

msteinmeyer

Hello camcamaro1991, thank you very much for your post, it was helpfull and made me jump into the retrofit for good. One time it happened to me that a dust cloud was expelled straight to my face when after a long parking I cleaned the dust out of my windscreen with the wipers and it got into the blower intake.

Just a little warning for anyone who might consider this mod: I think considering the plastic you have to remove as "very soft" sounded like a terrible lie to me. I spent over an hour cursing and finally I was only able to remove it using a dremel tool another 15 minutes. I don't know if my HVAC case was made out of a totally harder and thicker plastic, but it made me work quite hard. Puting the HVAC cover bolts back on was another unhappy duty, but I'm happy with the results however.