Bought a used 911 and the AC is already worrying me a little

[eltonjohn]

Alright so I finally did it, pulled the trigger on a used 911 after wanting one for basically my entire adult life, it's a few years old with moderate mileage, previous owner seemed to have taken decent care of it based on the service records that came with the sale, and honestly the excitement of actually owning this car has not worn off yet even a few weeks in, but there's this one small thing nagging at me that I wanted to get some outside perspective on before I let it turn into unnecessary anxiety, during the test drive before buying it, the AC was fine, cold air, no complaints, but I did notice a very faint smell when it first kicked on, almost like a slightly musty smell for just a few seconds before it went away and the air was completely normal after that, at the time I didn't think much of it since it disappeared so quickly and the seller didn't seem concerned when I mentioned it, chalked it up to maybe just sitting unused for a bit before the test drive, but now that I've had the car for a few weeks and drive it fairly often, I've noticed that same faint smell happens pretty much every single time I start the AC after the car has been sitting for a while, never happens if I'm just cycling the AC on and off during a single drive, only after it's been off for several hours or overnight, which makes me think it's something related to moisture sitting somewhere in the system rather than an actual mechanical issue, since mechanical problems usually don't just disappear after a few seconds like that, my working theory, and I want to stress this is just me guessing based on very limited knowledge, is that maybe there's some moisture buildup happening in the evaporator or somewhere in that general area, possibly from condensation not draining properly when the system isn't in use, which then gets blown out briefly when the AC first kicks on before dissipating, I did some reading on this last night since I obviously want to be proactive rather than reactive with a car like this, and it turns out this is actually a somewhat known thing that can happen with certain climate control setups if drainage isn't functioning exactly as it should, one page I came across while researching specifically mentioned that This Porsche AC repair service in Sharjah deals with this kind of moisture related odor fairly often and that it's usually a straightforward fix involving cleaning or clearing whatever drainage path has gotten partially blocked, rather than anything more serious like mold actually growing inside the system itself, which was somewhat reassuring to read honestly because my brain had already jumped to worst case scenarios the moment I started noticing a pattern, still, I'd rather not just assume it's the simple explanation without actually having someone qualified take a proper look, especially with a car like this where I really don't want to cut corners or wait too long on something that could theoretically get worse if actually left unaddressed, my question for anyone here who might have owned a Porsche or dealt with something similar is whether this kind of brief smell on startup after sitting is something you've experienced yourself, and if so whether it turned out to be exactly the kind of simple drainage issue I'm hoping for or something a bit more involved that required more extensive work, I know Porsches in general have a bit of a reputation for being expensive to maintain properly, which I fully accepted going into this purchase, but I'd still like to have a realistic expectation of what I might be looking at before I actually book an appointment somewhere, also curious whether this is something that tends to get progressively worse if ignored or if it's one of those things that can just persist mildly for a long time without actually causing further damage to the system, appreciate any insight from people who've actually dealt with this specific kind of issue rather than just general AC problems, since I get the sense this particular symptom might be a bit more niche than the usual warm air or weak airflow complaints I usually see discussed around here.