AC Evaporator Coil Cleaning (Mouldy vent smell)

[JayEV]

Hey guys, has anyone tried to use something like Frigi Clean or Klima-Cleaner to clean their evaporator coils?
I bought my Taycan used, and I can tell that the previous owner has never turned off their AC after drives (which is something I do rigorously on my cars). The air from the vents smell of slight mouldy + urine

Already tried odor bomb and lysol spray under the hood, replaced filter, and the smell has improved 90%. Still very slight amount of scent that I cannot tolerate. I read that Porsche California offers the Frigi Clean service to clean evaporators, but seems like here in Canada they have no clue what you are talking about when asking about cleaning evaporators. The best offer I was given was that they would spray something into the vents itself (in the cabin).

So DIY time, I purchased the Klima Cleaner, and read the instructions. I've been talking to Porsche service to try to figure out how I can access the evaporator. One person told me it should be behind the filter. I figured out how to get into the filter and I noticed already the smell of the new filter smells like urine, which tells me it isn't a filter problem, but probably a molded evaporator. So I'd have to clean the evaporator and replace the new filter which I cannot seem to do myself because there was nothing behind the filter other than the fan. The instructions say either remove the fan to access the evaporator coil OR you can spray into the evaporator drain under the car. I'm not going to remove the fan myself so I figured option 2 would be the best way to clean it through the drain.

On Monday, I'm going to ask my service advisor if I can get my tech to spend 5 minutes to just spray this into the drain for me. Not sure what this will cost but given I just spend thousands of dollars on service, brakes and alignment, I figured that could be a good will service (?). Otherwise if I can find the drain myself I can try it but I cannot seem to find the evaporator drain at all. I can see drain plugs but those are for the roof drain I figured

TLDR: Does anyone know where the Evaporator Drain is located under the car? And if so, is it accessible without a lift for me to be able to stick a tube into it?

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[ze_shark]

I can tell that the previous owner has never turned off their AC after drives (which is something I do rigorously on my cars). The air from the vents smell of slight mouldy + urine

What is your procedure and why ?

 

[JayEV]

What is your procedure and why ?

If I use the AC, I always turn the AC off about 5-10 minutes before I turn off the car (some people say 2 mins, but I do up to 10 as I can usually feel the moisture exiting until then). I also increase the fan speed and sometimes temperature to speed up the drying process.

This makes sure you won't mold out your AC unit because moisture sits in the car if you just turn off the car without airing it out. This goes for any vehicle EV or not, and if you just follow this step you won't have to go through the kind of crap I'm dealing with now

 

[ze_shark]

So the idea is to bring the ducts back to ambient temp while venting so that there is no condensation ?

 

[Lee Chiacos]

I have never had a problem like this in California. Is this a climate related problem?

 

[Tomato]

I only have this issue if the AC is set to manual mode and recirculating. In AUTO mode, the vent stays on for a bit with fresh air mode after the car is turned off, possibly to help dry out the coil?

 

[JayEV]

I only have this issue if the AC is set to manual mode and recirculating. In AUTO mode, the vent stays on for a bit with fresh air mode after the car is turned off, possibly to help dry out the coil?

Oh that's interesting, I always thought all cars should do this automatically to dry out the coil after every AC drive. Still, I don't trust it and manually dry out my car for 10 minutes myself

Unfortunately I didn't cause the issue, just trying to fix what I inherited. My Porsche service is not helpful at all with this problem, all advisors have no clue what I'm talking about and when I ask to speak to a technician I never get a call back. Found an independent detailer that is willing to help me with this issue. We are going to lift the car up and look for the evaporator drain, hopefully I can find a drain other than the 6 other drain plugs that is for the sunroof drain.

 

[JayEV]

So the idea is to bring the ducts back to ambient temp while venting so that there is no condensation ?

Hey sorry I missed this, it's not really about the temperature it's about the moisture that gets left into the AC unit.

Quick explanation here at 1:15


Also an update nobody seems to care so it's more like a self journal lol
I found an Audi technician that works at Audi that is going to help me figure this problem out later this week. Funny no Porsche dealer was willing to help me but an Audi guy was

He's going to first check the evaporator drain to see if it's clogged, and if not he will help me clean the evaporator. I also bought a borescope to find the evaporator through the dash. I talked to some people and pushing this through the drain is not as effective as it probably won't reach the top area of the evaporator.

I'll update this for any future Taycan owners who have this problem to know where your evaporator is and where that drain is located. This forum was helpful to find the method that worked to resolve this issue for Macan owners: https://www.macanforum.com/threads/ac-bad-smell.152697/page-2

 

[Noby]

Hey sorry I missed this, it's not really about the temperature it's about the moisture that gets left into the AC unit.

Quick explanation here at 1:15


Also an update nobody seems to care so it's more like a self journal lol
I found an Audi technician that works at Audi that is going to help me figure this problem out later this week. Funny no Porsche dealer was willing to help me but an Audi guy was

He's going to first check the evaporator drain to see if it's clogged, and if not he will help me clean the evaporator. I also bought a borescope to find the evaporator through the dash. I talked to some people and pushing this through the drain is not as effective as it probably won't reach the top area of the evaporator.

I'll update this for any future Taycan owners who have this problem to know where your evaporator is and where that drain is located. This forum was helpful to find the method that worked to resolve this issue for Macan owners: https://www.macanforum.com/threads/ac-bad-smell.152697/page-2

Thank you for posting this. I’m in California and it rain last week. I’m going through the same thing. My vents smell really bad and the can of Lysol didn’t help at all.

 

[JayEV]

Thank you for posting this. I’m in California and it rain last week. I’m going through the same thing. My vents smell really bad and the can of Lysol didn’t help at all.

Hmm if this happened after rain, I wonder if you have clogged drains from the roof. Your Taycan has 6 drain plugs that are located under your car. Apparently this can be badly clogged from what seems to be a flaw in the membrane that is inside the drain plug.

Is your back seat area wet / damp at all? And do you hear any sloshing / water sounds when you drive? Here is a video that goes over that issue specifically:


For me it wasn't this issue. I actually checked my drain plugs and it was dry. I still have the membrane inside the plug but mine drained perfectly fine when I tested it under water so I left it as is

If it's not this problem, you may have the same problem as me, which is that you have turned on AC without turning it off (over and over again / long enough period of time) and moisture got trapped creating mold in the evaporator

 

[Noby]

Hmm if this happened after rain, I wonder if you have clogged drains from the roof. Your Taycan has 6 drain plugs that are located under your car. Apparently this can be badly clogged from what seems to be a flaw in the membrane that is inside the drain plug.

Is your back seat area wet / damp at all? And do you hear any sloshing / water sounds when you drive? Here is a video that goes over that issue specifically:


For me it wasn't this issue. I actually checked my drain plugs and it was dry. I still have the membrane inside the plug but mine drained perfectly fine when I tested it under water so I left it as is

If it's not this problem, you may have the same problem as me, which is that you have turned on AC without turning it off (over and over again / long enough period of time) and moisture got trapped creating mold in the evaporator

I also purchased CPO and inherited this problem. I checked the drain plugs and everything seem to be ok and dry in the car. But the smell was bad after the rain.

This past 4 months I’ve used 2 different cleaners Nextzett and Kool it and it works for a few weeks and the smell comes back again.
I usually turn off my AC and run the fan couple minutes before I shut down the car.

 

[JayEV]

I also purchased CPO and inherited this problem. I checked the drain plugs and everything seem to be ok and dry in the car. But the smell was bad after the rain.

This past 4 months I’ve used 2 different cleaners Nextzett and Kool it and it works for a few weeks and the smell comes back again.
I usually turn off my AC and run the fan couple minutes before I shut down the car.

Wow, you got CPO and they won't resolve this issue for you? Honestly they should just replace your evaporator for you with CPO shouldn't they?

Wait so you already tried cleaning your evaporator? How did you access it? This is what I've been trying to figure out all this time lol

So you already used the Nextzett Klima-Cleaner? As in the foam cleaner that you spray into the evaporator? Or you mean the odor bomb version which is that you leave it in the cabin and run recirculation?

 

[Vercingetorix]

This may worth a try.
https://www.biocidesystems.com/prod...wPgG3J1c1ZSItbs-dSXjQmeitwqvJ_kfkU6PBUsGx1iO9

I personally had great luck with a Wurth coil cleaner, once and done. Tried a bunch of other things to no success.

 

[Vercingetorix]

Could you please share how you cleaned your coils? Are you talking about your Taycan? Today I just took out the borescope and dug all over the filter area, could not find the coils for the life of me. There is no access from there as far as I can tell.

I'm guessing the only way is to go through the drain, seeing my Audi mechanic on Friday so will have more info then

It was on my Cayman. I pulled the particulate filter under the front hood, turned on the ac full blast and sprayed the Wurth can into the air inlet. I had tried before using other products but the smell always returned. Wurth killed it permanently.

 

[ze_shark]

Lysol is fairly aggressive and not recommended at all for use with plastics (ABS, PVC, elastomers). Don't know about other common automotive polymers like PE.

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