aisalit

Hi There,

I'm new to Lexus Club and I have enough experience with cars, however, I have this interesting issue, my car keeping the external air 24/7 even when i press the Internal Circulation button (I have two separated buttons) with A\C either On or Off, I always smell whatever outside. My 2015 GS 350 is almost new with few miles though, the dealer has no idea how this could happen, they checked the sunroof, doors, blend door movement + closure and windows all are health, and still having outside smells (cars exhaust + flowers + sewerage etc.) anything just coming inside right away.

duraiaras

Yes. I do have this issue of odor like school bus diesel or pickup truck diesel getting in.. I talked to dealer and they denied it. Living with it.. Staying far behind trucks or buses.

spoogenet

No car is air-tight so you can't expect to be completely isolated from external smells. But if the air is on recirculate, it should be significantly reduced.

Have they confirmed the air filters are properly installed?

DallasDave

iTrader: (1)

There also must be a "door" of some type to redirect the air when switching from OUTSIDE to RECIRCULATE. It wouldn't be unreasonable to think this mechanism is failing somehow. On my wife's MB, it's easy to see this operation. There's a trap door that closes and cuts off the flow of fresh air when the recirculate button is pressed. I've noticed it when replacing the cabin air filters.

This may be a place to start (yourself or with the Dealer). The cabin air filter on the GS is accessed from the glove box. If you remove the filter and switch from recirculate to fresh, I wonder if you can observe the "door" operation from this area.

aisalit

yes, they check the air filter and it's ok.

aisalit

Excellent note, they also test it this way, opened the air filter in the glove box and pressing the circulation button while observing how the door is closing and it's also fine, at least it's moving.

aisalit

There's must be a solution for this, don't accept it, you own a wonderful car that should prevent such an issue.
at least now I know that you having the same issue, I'll let you know if I reached the perfect solution.

Shiloson

Hello everyone. I'm having this same challenge with my 4th Gen GS350. Any update please?

Thanks

bclexus

When the RECIRCULATE button is pushed and light lit the inside cabin air just keeps recirculating. No outside air comes in. When the AUTO button is pushed and light lit the HVAC system will determine how often the system remains in recirculate mode versus outside air mode based on cabin temperature, setpoint temperature and outside temperature..

The closer the outside temperature is to the cabin setpoint temperature the more often the HVAC system will go back and forth between recirculate mode and allowing outside air to come in. On the other hand, if it's 100° outside and the setpoint is say 74° the A/C will be On and the blower will be at or near 100% speed - this will have the HVAC system remain in recirculate mode as you do not want hot outside air coming in. Similarly, if it's 15° outside and the setpoint is say at 76° the heat will be On and the blower will be at or near 100% speed - this will have the HVAC system remain in recirculate mode as you do not want cold outside air coming in.

If the system's setpoint is set at 72° and the cabin temperature reaches that 72° setpoint and it's also near 72° outside - if the HVAC system is in AUTO mode - you'll see the system mode lights change every so often indicating the system is switching between recirculate mode and outside air mode.

Shiloson

In my case, I'm not using the auto button. I manually set the fan speed and chose the recirculate option. Sill, air (smoke, etc) from outside comes in.

909

Monitor your recirculate button.
Our GS's will periodically switch from recirculate to fresh air on its own.

jgscott

iTrader: (1)

If it is extremely hot outside, I'll run recir for a min or 2 only. I run Auto but outside air in only. I offset the slightly reduced air not using recir in the summer by keeping a clean Carbon cabin filter in my car every 3-4 months.

Running Recir sometimes gives people headaches, and I always love incoming fresh circulated outside air coming in. Also running Recir is also a guarantee that you will get the stale sour smell coming out the vents eventually. I can not live with a nice car smelling sour air. That sour air smell also almost assures that there is some mold and/or mildew and other contaminates coming out the vents when you use them also.

bclexus

Roll your window up!

Seriously, in recirculate mode the ductwork damper doors for outside air are closed...unless your car's damper door servo motors are defective, which indeed they might be...

The Lexus HVAC system is very complex and intelligent. You may think you're smarter by making manual adjustments, but by doing so you're just fooling yourself.

Shiloson

Is there a test or scan I can do to ascertain if the damper door servo motors are defective? I've been using this car for a while and this just started happening.

Thanks.