K_Bro

Bought a new 2007 RL two months ago. About a week ago I noticed that 7-8 minutes after starting the engine with the A/C on full auto or recirculate, there is a musty smell coming out of the A/C. Interestingly the delay is fairly consistent.
Yesterday I noticed that I have to crank up the temperature for comfort. Whereas earlier 73 deg was comfortable, now cold air blasts out at 73-76 and I have to bring it up to 79 for the same sense of comfort as before.

Ambient temp has been in the mid 80s for the past week, the car is not hot inside when I startit (covered parking) so there is apparently no other confounding variable.

Does anyone have a suggestion on what might be going on? Thanks.

miner

The musty/mold smell is caused by not properly drying out the condensor after use - shutting off AC 5 minutes before turning car off and letting ambient air dry out the unit. You can try turning your AC on full blast (not recirc) and spraying Lysol or someother mold destroyer into the AC vents on the outside of the car near base of windshield. You should use at least half of the can.

dwboston

Agreed. You could also try swapping out the cabin air filter, and maybe spraying some Lysol in there before putting the new filter in.

GLowrdr

I'm not saying this is incorrect- BUT..... I have never once in my life shut the a/c off 5 minutes before I got where I was going, and have not had an issue. Perhaps there is some "break-in" for a/c and heater components? The same way your car will stink for a while after getting a new exhaust etc...

As for the lysol trick - hell no. I would rather live with the musty smell and get an air freshener in my car then to spray <half a can??> of lysol in my fresh air intake. There goes your new car smell, and it'll be weeks if not longer before your car stops smelling of the gagging scent of lysol.


Do what you want (I see the purpose of the Lysol, just not my thing)

dwboston

I've used the "lysol trick" in the past and it doesn't take that long for the lysol scent to dissipate. Besides, his "new car smell" is being overpowered by the mustiness anyway. I think changing the cabin air filter will make a difference.

gavine

Every car I've ever owned has had a musty smell when I first turn-on the A/C. I didn't know about the 'turning-off-5-minutes" idea but that's a good one. I'm going to start doing that.

I don't think it's a problem with your system...it's a common thing. Also, the musty smell usually goes-away within a few minutes. Does yours last longer than that? If so, the source might be somewhere else.

K_Bro

1. Yes, the smell only persists a few minutes, either bevause it genuinely dissipates or because the sense of smell accommodates (that's a medical fact BTW, that the sense of smell accommodates quickly).

2. It is completely out of the question that I pour lysol (half a bottle or not) into the AC. I am a pulmonary doctor and I very seriously doubt that that's good for you. This should never be an acceptable solution regardless of how tempting it is. BTW I had driven 4 cars before this one (VW, Ford, Honda, Cadillac) and none had the smell. The manufacturer needs to find an engineering solution (that does not involve inhalation of caustics) if it is truly common.

3. Shutting down the AC 5 min before may work but certainly the user should not be burdened with this. All I want is to drive the car from point A to point B and have a pleasant ambient temperature without any intervention from my part.

4. Changing the filter sounds like a good idea but this car is less than 3 mos old. How often will I have to do this?

Chas2

The car is only 3 months old from date of purchase. Who knows how old it really is? Need to see the manufacture date.

Regardless, moldy, musty smell is a common problem on many cars, especially if they have not been run for awhile. The dealer actually has a spray, like lysol, that removes the smell by killing the offending organisms which are likely living on the condensor surfaces. By the way, you do NOT use liquid lysol under any circumstances. There may be other issues, like a partially blocked drain which is allowing water removed from the air by the condensor to build up, etc. Changing the cabin air filter may also do the job, but this is a dealer warranty item, and they should be able to handle it easily and happily.

Shutting down the a/c five minutes before shutting the car off is ridiculous, especially in hot weather. You did not pay $40-50K for a luxury car to put up with this...

neuronbob

While in theory shutting down the AC 5 minutes before you reach your destination might be a good idea, I've never done that in any car I've owned.

Chas has an excellent point....my RL sat on the dealer's lot for about three months before I purchased it. Who knows how long the OP's was on the lot, or on another lot? That alone would be enough to cause the problem.

I'd start with the air filter and if no go, then it's dealer time. Luckily, this is usually not a difficult problem to resolve.

TampaRLX-SH

I tend to leave the recirc on, which limits outside air flow into the vents. With the humidity and rain in Florida, outside air only introduces moisture into the ducts and when cooled, forms condensation in the ducts which will grow mold. Then you have moldy smell.

By leaving the recirc on, I rarely have any smell at all. On days when humidty is very low, I will turn the recirc off and air out the ducts with outside air.

The smell is mold growing, and moisture in the ducts feeds the mold. I cannot attest to the remedies for cleaning out the smell as I have not accumulated any noticeable smell from the A/C ducts.

dwboston

No one is suggesting using "liquid lysol" - try spraying some in the fresh air intakes and the cabin air filter compartment when the filter is out, then running the fan on high for several minutes while not sitting in the car.

Your car is an 07, but only a few months old, so it's possible it sat on a lot for a while. The filter should probably be changed every 15,000 miles or so. You'd be surprised how dirty they get after a short time. I change mine at least once a year. It's an easy DIY and takes less than 5 minutes on the RL. Dealers charge an arm and a leg to do it.

K_Bro

Spraying, not pouring half a bottle (see post by miner) of lysol is what I meant (sorry for the confusion). Still doesn't sound right.

Agree w/ Chas2 that shutting down the a/c 5 minutes before stopping is ridiculous. You don't need to do that in an accord or passat, why should you have to do it a luxury car. Plus I live in AZ, try doing that in 110 degrees.

getakey

Have not had the smell problem, but I have complained before about the lack of temp control in my 05. Disappointing to learn that still a problem in 07. Seems to be fairly common that the system waits approx 10 minutes and then decides to blow either very warm or very cold air compared to what the settings are and then have to adjust temperature settings. In my 05, I am used to resetting temp in the morning to 68 so as not to be overheated and then adjust to 73 in teh evening so as not to be over cooled.

dwboston

This isn't a widespread issue with the RL - I haven't had the problem with either RL (05 or 06) that I've owned. Take it into the dealer and see what solution they suggest.

Here is another suggestion :

AutoTips Fresh Air Tips

For those who live in humid areas, a common complaint is a musty odor from the air conditioner or heater, often after the car is parked for a while. One cause of this is moisture left in the drain pan after the heater or air-conditioner is shut off. Many U.S. cars run the air-conditioner in the defrost position to remove moisture from the air, so your air-conditioner (a/c) compressor may be running even in the winter.

What to do: There are many different remedies people have used, you can try this one for free. The key is drying out the air-conditioner before you shut the car off.

American cars: In the winter, if you don't need the defroster, run with the controls in the heat or vent position, possibly for the last few blocks before you park your car. On most American cars, this will bring in fresh air, and give the pan around the air-conditioner a chance to dry out. In the summer, for the last few blocks before you shut off the car, run with the a/c off, and vent on.

Cars with a Fresh or Re-circulate lever (found on many imports): Be sure the lever is in the fresh position for winter, and if you don't need it for extra cooling, the same in the summer. Often these cars have a switch to allow independent control of the a/c compressor, so you can merely shut it off a few blocks before you stop the car.



Other Possible Causes: Air Conditioners in cars generally have a hose to drain off the condensation from the air conditioner coils. If this hose becomes plugged, water can collect in the air conditioner area and take a long time to dry out, permitting molds, etc. to grow. The drain hose is normally on the engine side of the firewall, and may not always be easily accessible to clean out. You may need to take the car to a dealer or auto shop to have this cleaned. Leaks in the air conditioner condensate area onto the carpet can leave damp spots for mold to grow.

dwboston

Do you get a little puddle of water under the car after running the A/C? If not the drain could be clogged, causing the musty smell. Apparently it's more common in dry, dusty areas. I assume AZ is dry and dusty with the desert and all.

Don Melcher

I just did this on my wife's ex car ('01 Solara) that was smelling like gym socks when you first started it - worked like a charm and the Lysol odor was gone within the hour.

Howsumever - I started the car, opened the windows, turned the A/C system up to full blast with outside air intake, then sprayed Lysol into the intakes below the windshield, and let it sit there running that way for about 15 minutes without my being inside.

dwboston

Exactly. I did the same thing in my old 03 TL-S. Just stay outside the car for a few minutes with the fan on high.

Don Melcher

That being said - it sounds like there are other things going on ("too cold") and with a car so new I would take it back to the dealer and let them deal with it. They will probably use the Lysol method - I learned it from a Honda dealer when I complained about the problem on our 93 Accord Wagon - what a great little car - wish I had kept it.

K_Bro

Any thoughts to why is the AC too cold?

UW RL

can anyone post a picture of the location where you would spray? I do have a product called Wurth AC treatment... I need to know where exactly I will need to point the can at. Thanks!

2007AcuraRL

There are several commerical chemicals that you can introduce to the outside of the evaporator coils to eliminate the odor.

I still have a can left of a special substance I once ordered through a Mopar parts dept some time ago. It was very expensive at almost $50/can but it worked very well. It coats the outside coils with a trace coating of some material that both inhibits mold growth and makes the surface of the coils very slick so water doesn't stick and linger on them. It comes out as an atomized spray (ie. a fog) and gets applied after you heat the coil up for about 5-10 min. I access the coils the same manner as you do for replacing the cabin filter.

I also have another chemical that I bought over the internet from a company named Ultrashield that worked too. If I recall, it didnt last as long as the Mopar stuff, which worked for over a year, but it was much cheaper so you could reapply it a few more times for the same cost. http://www.ultrashield.com/products_AC.htm

GoHawks

Another data point. I remember reading in the owner's manual of my '01 TL that the A/C compressor will always run (assuming you have it in Full AUTO mode) as long as the temp is above 32F in order to remove humidity. Once the temp drops below freezing, the compressor will no longer run.

My guess is that as temps do get colder you actually want some humidity in the air. Hence why people turn on humdifiers in the winter.

I'm sure someone has a more technical explanation.

As for blowing cold air. Don't forget that the RL has a solar sensor as well. Even on cold days, if you have bright sunlight coming into the cabin, it's not uncommon to feel the system blowing air to try and maintain the temp setting. It just feels wierd to feel cold air blowing, but it may be legitimate in order to maintain the desired temp.

As for the musty smell. I'm just begining to notice a faint trace of it in my '06 (24K miles), but it's gone rather quickly. I'm probably due for a cabin filter replacement. That seemed to address the issue when I had my TL.

AZRL

I have the same problem with my 05 RL. I live in Arizona, the A/C unit runs full time in the summer months, with no smell. Turning the A/C off 5 minutes from destination is not an option during the summer. Now that the temps are cooling, I experience the smell for the first couple minutes after startup, then it goes away. I have also changed the cabin filter, but it did not help. Perhaps the lysol spraywill work. As information, my friend with a Lexus SC has the same problem, but much worse smell.

Strategr

I had the same musty smell with my 07 RL early on.

Acura had me take it to the dealer. The dealer spayed Ozium to fix the problem, and it did work. And the smell isn't near as bad as using lysol. from my past experience with other cars, lysol does not usually fix the problem for very long. Ozium resolved it- no issues for months so far.

Dealer was very nice about it, although they said they could not detect the smell. I did get a TSX to drive for the day- that made me feel very happy I decided on getting the RL.

We have a Mazda as well, and on that similar forum site, there is a fix they have to coat the a/c evaporator coils with a spray that prevents the mildew or mold from building up.

There are air intakes at the base on the windshield and interior on the floor under the dash for the recirculate mode.

K_Bro

OK, seems like the mustiness has an easy fix.

What I also noticed -- though it was sidelined in the thread -- that the AC blows colder than expected, at high flow.

Example: outside is mid 80s (balmy weather in AZ). Set the AC on full auto 73 degrees and it blows cold air on 5 of 7 bars (in terms of fan power). This is not only when you turn on the engine, but even 20-30 minutes into the ride, when you would expext the flow to decrease somewhat. The comfort temperature is somewhere in the high 70s -- it was for me 72-73 deg -- and I have to manually dial down the fan power to 2-3 bars.

Is it possible that the thermostat or other sensing or feedback mechanism is off?