So I always turn the AC off and leave the blower running as I'm nearing my home (I live in Texas) to try and give the system to blow outside air instead of recirculated air across everything in the system and I've never had it smell like anything even if it sits parked for a while. I don't know if that would help but it might?! (Nearing home>click AC button>leave fan running>arrive home>enter garage>put car in park>unbuckle>shutoff fan>shutoff car.

I do the same thing in my wife's car and we've never had smells in that vehicle either but I've had other vehicles that if I didn't do this procedure then I'd get funky smells occasionally like wet/slight mold/vinegar/etc.......

 

This is key, I am going on a month without my vinegar smell issue after paying closer attention to shutting off the AC and leaving the blower running.

The goal is to return the ice cold evaporator to ambient temperature before the car is shut off so that the cold evaporator does not sit and form a ton of condensation as it slowly gets back to ambient (Think of the water formed on a cold glass/can sitting on the counter). If not blown by a fan, the condensation can sit and form mold and other smelly organisms. I guess some vehicles are better than others at draining, which is why some are more susceptible to this issue in warmer climates.

Hyundai agrees as they are implementing an automatic system to perform a similar process:

https://www.autoblog.com/2020/07/28/...RQeInD0NxofPVK

"The last piece of tech we’ll explain is the after-blow. Hyundai says the end goal here is to reduce mold growth in the air conditioning system, which if left untreated, could cause unpleasant odors in hot weather. Here’s how Hyundai is fighting the mold: “After the engine is turned off and the condensate on the evaporator drains naturally for about 30 minutes, ‘After-Blow’ activates for 10 minutes to dry the evaporator and any condensate leftover in the air passage. The air-conditioning system automatically allows influx of outside air during this time to prevent humidity from building up.”

 

This is exactly it! Excellent find @BMGS !

 

Just picked up a CPO this weekend and have this vinegar smell already. Given that it's a used vehicle, I wasn't surprised at all.

Did this yesterday;

1. Removed cabin air filter and open both doors.
2. Turned on AC to cold full blast - waited 3 minutes until I see water dripping under the car.
3. Sprayed 8oz of 70% isopropyl alcohol on outside a/c vents.
4. Turned off a/c and let it sit for good 2 minutes.
5. Turned on a/c to cold and let it run for good 5 minutes.
6. Turned off a/c and leave fan on full blast.
7. Repeat process but under a/c hot setting.
8. Replaced cabin filter with new one - sprayed 70% isopropyl alcohol on the new cabin filter.

This morning when I turned on the car. No smell at all. Not even a left over alcohol smell.

Btw, I put half a sack of charcoal in an open box and place it on the rear seat - left it overnight. Took away all the smell of the car.

So it's now ZERO smell in the car.

 

Very nice, what type of charcoal did you use?

Sounds like you solved the existing issue but be sure to turn off the AC and keep the blower on for a few minutes before shutting down to prevent future issues. Before I fully understood what was going on and the importance of the process, my cleanings had only lasted a couple weeks.

 

Regular charcoal that you can buy from any hardware or grocery store . I didn't chose the quick ignite coz it's summer in my area and I don't want to barbecue my newly acquired car.

And yes, I forgot to mention - gotta maintain to prevent the smell coming back by turning off a/c and leaving fan blower to max (for a good 2 minutes) before turning off the car - this is a necessity! Thank you for mentioning it.

 

Excellent and agreed on the quick ignite! The alcohol sounds like the best method to keep the residual smell neutral. I used a formulation from the auto parts store that had a "fresh" scent. Its better than the vinegar smell but it lingers for a while. Hopefully the charcoal will absorb it and the prior owner's crappy air fresheners.

 

Where is the evaporator drain line located under the RC 350? Thanks

 

Its above the transmission, its very difficult to access. I am kicking myself because I had a two day subscription to TIS and I forgot to look for additional documentation on the access.

 

Since the evaporator drain tube exits underneath the transmission I gave up on the purchase of Toyota AC Refresher Kit and decided to try good old Lysol spray in the intake vents underneath the wipers/hood. I cycled the AC settings while spraying the Lysol. It worked!! Smell was gone today.

 

Hopefully the smell won't come back in two weeks. Seems the most effective way to prevent it from coming back is by turning off the A/C one minute before turning off the car - but this practice often get forgotten or skipped. Depending on how much bacteria or molds already living in the evaporator, it may take two or three cans of Lysol spray before the smell goes completely gone, meaning flushing all dirt from the evaporator core.

 

Its still working well for me a few months later. I try to shut off the compressor as early as feasible as I near my house and blast the fan. I don't think it needs to be done for shorter trips out but probably should be if the car will sit all day or night.

What I noticed also works is just blasting the heat for 10-15 minutes. I do that on my wife's car (NX200t) and it works. There is no way she is going to shut off the compressor etc.. so luckily the heat blast every couple weeks helps. I just got in some medical grade 99% IPA to clean out the evaporator as well. Her car has the sweaty sock smell whereas I had a puke smell initially that was knocked down to a vinegar smell before I got rid of it completely lol.

 

That's exactly what I had when I got the car and is now mild vinegar smell when A/C is on. No smell when it's off (Fan/heater on). I also have an IPA in a car which is periodically getting sprayed (outside windshield vents) which helps for a day or two but comes back again after that. Car is currently a garage queen right now since I'm currently wfh. Can't wait for the winter and use the heater to finally kill the smell.