In cabin condensation - Page 2 - Boxster/Cayman - PistonHeads UK

This is my first winter with my 718 Cayman so on a bit of a learning curve with it now things are getting colder. Probably should mention I live in Scotland where it is a) cold and b) wet With the temperature dropping a bit recently, i've noticed a lot more condensation inside the cabin. Yesterday the car was fine when i started it, drove it half an hour, parked up for a few hours and when I got back the inside of the windscreen was covered in condensation - almost to the point of dripping. I always have the AC and it isn't on recirculate. Have looked on Google and there doesn't seem to be any obvious drain hole issues on the Cayman. Have had a feel and there aren't any obvious wet spots on the carpets. Quite a few people say it's just one of these things and to get a dehumidifier bag to leave in the car to deal it, but i'd rather try and find the cause if possible. Does anyone else get this on their coupe? Any tip/tricks/suggestions? Edited by jeebsy on Sunday 26th November 08:55

I have always assumed it is condensed water on the evaporator that hasn't cleared from the previous drive. Mine has done this every winter from the day I bought it, new, 12 years ago. Just allow an extra few minutes to demist before moving away.

if you have carpet mats are they wet? you can bring in a fair bit of water on your feet i always try and air out my cars on a dry breezy day , seems to help a little

I suspect you have a leak somewhere. As above, check carpets in front footwells and behind both seats.

Try changing the pollen filter. I always do this in Autumn & rarely get major condensation problems (although I'm a soft southerner so not as cold & wet as up north)

gsewell said: I have always assumed it is condensed water on the evaporator that hasn't cleared from the previous drive. Mine has done this every winter from the day I bought it, new, 12 years ago. Just allow an extra few minutes to demist before moving away. I only really drive mine at weekends and it's always noticeable after driving it so wonder if it's this. If it was a leak you'd expect it to get worse the longer the car was sitting? Can't feel any obvious wet areas on the carpets anyway.

jeebsy said: I only really drive mine at weekends and it's always noticeable after driving it so wonder if it's this. If it was a leak you'd expect it to get worse the longer the car was sitting? Can't feel any obvious wet areas on the carpets anyway. I had a leak due to faulty rear sun roof drain and hadn't noticed wet behind passenger seat (it was soaked). My symptoms were no condensation when the car was left sitting, but dripping screen after parking up following a run. Takes an age to clear then all seems well. Until the same thing happens next time. I never noticed any condensation if the car wasn't driven.

This will sound strange, but taste the condensation, if it is sweet you might have a lack on the heat exchanger, they are known to leak but doubt it on a 718 due to age. But test to count this out. The air conditioning system on these is known to be a bit pants, Forever Manual on Youtube discusses this a few times. I quickly found this, which was the first time he talked about it.... https://youtu.be/BYxmdAwtZW4?si=GuSk_Z4ociaXsUEH&a...

Discombobulate said: I had a leak due to faulty rear sun roof drain and hadn't noticed wet behind passenger seat (it was soaked). My symptoms were no condensation when the car was left sitting, but dripping screen after parking up following a run. Takes an age to clear then all seems well. Until the same thing happens next time. I never noticed any condensation if the car wasn't driven. from a quick google this morning, the cayman doesn't seem to have any drains that overflow into the cabin - the ones on the boxster are known issue but doesn't seem to be a problem on the cayman. will i'm pretty anal about the car and hoover the inside pretty thoroughly ever week or two, and haven't noticed any damp patches but will keep a watch out for them.

Not very helpful but it may be a 718 thing. Maybe not to the degree you are describing, but all three of mine suffered worse than average condensation compared to other cars I’ve owned. Was very winter weather dependent. Some days terrible, others nothing.

neilf said: Not very helpful but it may be a 718 thing. Maybe not to the degree you are describing, but all three of mine suffered worse than average condensation compared to other cars I’ve owned. Was very winter weather dependent. Some days terrible, others nothing. yesterday was the worst it's been, but it was also barely above freezing and the first seriously cold day of the year so not taking that as typical. a few folk on the 718 forum said that's just how they are and to keep one of those wee dehumidifier bags in the car so got one today. maybe it's just the residual heat from the engine in the cabin hitting the windows when the temps drop and there's no air con running to move the air?

jeebsy said: from a quick google this morning, the cayman doesn't seem to have any drains that overflow into the cabin - the ones on the boxster are known issue but doesn't seem to be a problem on the cayman. will i'm pretty anal about the car and hoover the inside pretty thoroughly ever week or two, and haven't noticed any damp patches but will keep a watch out for them. That's good news. The front drains, if blocked, will led to ingress into the cabin. I don't think the Cayman has any in the rear that could. And the bottom of the doors can get soaked too. Worth a feel.

I get this on my one too, not dripping but the rear window and rear side windows will get a decent covering of condensation when left after a drive. I’m down south but it’s still cold enough. I always put this down to the large amount of glass area in the cabin, especially with the rear window directly over the boot but have always put this down to normal behaviour.

Discombobulate said: I had a leak due to faulty rear sun roof drain and hadn't noticed wet behind passenger seat (it was soaked). My symptoms were no condensation when the car was left sitting, but dripping screen after parking up following a run. Takes an age to clear then all seems well. Until the same thing happens next time. I never noticed any condensation if the car wasn't driven. You have a Cayman with a sunroof? Bliss I'm looking for one of those 80's moonroof kits and a big can opener.

Jefferson Steelflex said: I get this on my one too, not dripping but the rear window and rear side windows will get a decent covering of condensation when left after a drive. I’m down south but it’s still cold enough. I always put this down to the large amount of glass area in the cabin, especially with the rear window directly over the boot but have always put this down to normal behaviour. I have the same, it is worse after I have collected fish and chips ... maybe that's a clue ? On Saturday I collected "six times" and it was particularly bad. I have not detected any coolant leakage ... so it's either limited aircon or the large glass area or ???

Had the same on my 981 and now 718, they all do that sir.... Already mentioned but I would check the drains are clear, I had a 987.2 Boxster S some years ago and there was water ingress into the cabin due to a blocked drain, fried the ECU under the passenger seat and caused all sorts of damage to the car. I had a quick drive in the GT4 yesterday and had to wait a few minutes for the screen to clear, probably not a bad shout putting a dehumidifier block in the car.

I assume that there are no drain pipes on a Cayman ??

ChrisW. said: I assume that there are no drain pipes on a Cayman ?? Limited information - certainly none at the rear like the boxster, and the front shows drains on the diagram but apparently there's only one with a pipe. This thread is about the best I've found on it -https://www.porscheclubgb.com/forum/tm.aspx?m=1136608 The guy says the only one with a pipe is the fuel cover, the ones on the cowl just drain straight out. Obviously they could still get blocked but they seem a bit more open. I'm off work on Wednesday so will try to get a good butchers then. Edited by jeebsy on Monday 27th November 12:53

This is the first winter with my GT4 and the condensation is ridiculous - to the point where I can't do my 10min drive to the gym in the mornings as it just doesn't clear up. I'm considering getting one of those dehumidifier cushion things from Amazon but how well do they work?

I've 2 in the passenger footwell. Works ok for me but also consider using this on the inside of your windows. https://www.cleanyourcar.co.uk/gyeon-q2-anti-fog

jeebsy said: ChrisW. said: I assume that there are no drain pipes on a Cayman ?? Limited information - certainly none at the rear like the boxster, and the front shows drains on the diagram but apparently there's only one with a pipe. This thread is about the best I've found on it -https://www.porscheclubgb.com/forum/tm.aspx?m=1136608 The guy says the only one with a pipe is the fuel cover, the ones on the cowl just drain straight out. Obviously they could still get blocked but they seem a bit more open. I'm off work on Wednesday so will try to get a good butchers then. Edited by jeebsy on Monday 27th November 12:53 I've had a look and that would make sense Thankyou !!

I just saw a video on yt that suggested turning he ac off for the last 10 minutes of a journey to clear the evaporator. I'll try this next drive.

Just a thought here. Have you got the standard air con or the automatic dual climate? Speaking to a mate at Porsche, they think that the standard system doesn't measure humidity, obviously the automatic climate is a dehumidifier too, as is the standard one, but that one is not sucking enough water out of the system as it is not monitoring it.

My 981 Cay lives outside, and doesn't have condensation, summer nor winter. I don't have the sir-con on as a matter of course... it makes the screen cool and prone to condensation as a result. My wife uses hers (in a GTi) and it's a PITA on a cold evening to have condensation when were going out, and having to wait 5 mins for the air con to get going and clear the screen before setting off. If I need to use air con in mine outside summer, I switch it off a few miles from home so that there's no water in the system. to find it's way to the screen on startup.

One thing I thought of last night re condensation in the cabin is that the coolant cap 'could' be the issue if it's not seated properly. It would be interesting to hear from Boxster owners if they have the same issue given the coolant cap is not incorporated into the cabin.

As a pressurised system, there would be a big puddle if there was any sort of leak.

scrounger73 said: One thing I thought of last night re condensation in the cabin is that the coolant cap 'could' be the issue if it's not seated properly. It would be interesting to hear from Boxster owners if they have the same issue given the coolant cap is not incorporated into the cabin. The only problem I have with my coolant cap is sometimes how tight it is ... I have been known tu use a large adjustable spanner and a rag to avoid marking the cap where the jaw of the spanner engages ...

I don't like to quote myself, but this is really important. There are two weak points on these cars, the heat exchanger and the coolant caps. Both can have the tiniest of leaks, like goes from max to min on coolant level over a few hundred miles. I didn't consider the coolant cap, because I was thinking 911, but yeah, could be an issue on the Cayman, so well worth checking you have the latest one. The heat exchanger leaking leaves the car dripping inside. I would definitely taste the condensation to check it is not sweet. Ed.Neumann said: This will sound strange, but taste the condensation, if it is sweet you might have a lack on the heat exchanger, they are known to leak but doubt it on a 718 due to age. But test to count this out. I would guess one of the main issues is just how small the cabin is, if the outside is very damp, and you get in with damp clothes that moisture is going to go into the cabin. Also, as I said, apparently the system that is not dual zone doesn't monitor the humidity in the car, therefore there is no real dehumidifier in there, which seems a massive oversight in this day and age. I would be interested to know if those with an issue have dual zone climate?

One other thing. Just as you pull in your street undo the windows. Get the cabin temperature down to as close to the outside as possible. Jump out with it 22ºc in the cabin and 3ºc outside and you will get the ice in glass on a beach effect almost immediately. That water is then going nowhere until you get back in and dry it out again.

I think the marketeers have done their job well, Climate control and AC are more or less the same. Both have cooling using the compressor which tends to dry out the air. Neither monitor humidity. Controlling humidity is *hard*! Really hard! Climate control adjusts temp actively using engine heat AND compressor. Simple "AC" is just open loop... set the temp and choose whether compressor is on or off. That's it. So both will dry out the aitr when the compressor is on. I have normal AC in my BGTS...drys out condensation quite effectively. My wife's BGTS has dual zone. Much the same. Both steam up and both are a PITA when the weather shifts temperature rapidly...can take minutes to clear. And sometime a cloth! Had the same in my old BMW rag top and my wife's old Merc C coupe...insane! It would steam up just by looking at it Dripping wet. And a brand new car.

I have had 2 718 Cayman's and they have both been bad for condensation in the winter.

Have you tried closing all the centre air vents during winter?

Mine is dual zone climate so should in theory be checking humidity too. It's not been as bad as the day which made me post but that was the coldest day so far, and someone on the US forum posted part of the manual which says the AC doesn't work below two degrees so maybe that was just a bad set of circumstances. I did get a dehumidifier bag from Halfords for 7 quid or something to try and haven't had a super wet window since, - there's still a bit of light condensation but nowhere near WTF levels. On the coolant cap, did they change the design? Mine's a 2018 so will be the earlier one if so.

Ed.Neumann said: One other thing. … you will get the ice in glass on a beach effect almost immediately. What?

Maxym said: Ed.Neumann said: One other thing. … you will get the ice in glass on a beach effect almost immediately. What? I just mean, if you have glass that is freezing cold one side and warm the other you will get all the moisture in the air condensing on the warm side. Basic physics. In winter it is damp, and we crank the interior of a car up to 22ºc or so, then jump out, turn all the heating off, and the dehumidifier (the aircon), and hence all the moisture condenses on the glass. I mention a drink with ice on the beach as you see it happen almost immediately, it is an extreme, and something we all notice even if we don't think about it.

Ed.Neumann said: Just a thought here. Have you got the standard air con or the automatic dual climate? Speaking to a mate at Porsche, they think that the standard system doesn't measure humidity, obviously the automatic climate is a dehumidifier too, as is the standard one, but that one is not sucking enough water out of the system as it is not monitoring it. I've had both systems on a 981 and 718 Cayman, same result.

I’ve found a very simple solution - I run it with AC off. Job done. Or, last 5 mins of your journey having had the AC on just turn it off and let the system clear the moisture. Works a treat. Have to say it’s a bit disappointing to have to do so though.

Does anyone else get condensation in the dials? Both in the main instrument cluster and also in the central clock dial. It’s only very mild but it’s noticeable. I don’t even get that much on the windscreen, but those dials often fog up slightly and have a little dampness in them.