Moisture / mist / condensation on windows etc

[Rikki]

Hi there, just bought a used Cayman from Sytner BMW in Birmingham (2 weeks ago) and Ive found that over the past couple of weeks a strange residue has appeared on the inside of the windows. I'd noticed a discolouration of the plastic / fake alloy engine cover trim (at the top end, not down nearer the hatch for the oil and coolant) and I've also spotted the metal luggage rings had a little rust on them (though these were evident when I picked the car up but I didnt think it was an on going issue perhaps caused by something strapped down leaking in the past).



(Quarter glass image is my finger smearing down the glass to clear the residue)

Just wondering if anyone has any ideas on this one and if its common?

Ive checked the oil and coolant filler necks for HG signs and everything seems ok there, no oily vapour etc.

Many thanks

Rikki

Edited by Rikki on Sunday 25th May 23:32

[996TT02]

Is the aircon working all the time, as I assume it should be?

Actually, rephrase that, is it working, check it out.

Aircon dries out the air.

Unless you have a water leak and the carpets or something else are wet.

[kev b]

Check the carpets, they may be damp through to the sound deadening if an over zealous valeter has soaked the carpets whilst shampooing them.

I am assuming you cannot smell antifreeze as a leaking heater will wet the interior and coat the glass inside.

[Rikki]

996TT02 said:

Is the aircon working all the time, as I assume it should be?

Actually, rephrase that, is it working, check it out.

Aircon dries out the air.

Unless you have a water leak and the carpets or something else are wet.

When I bought the car I turned the air con off - force of habit from ye old days of extra fuel consumption I suppose.

My previous car was a 2004 gen 1 Boxster S and I never ran the air con on it unless it was really hot and I didnt have the top down and I never saw anything like this with residue appearing on the glass and I ran that car for nearly 5 years.

Ill investigate carpets etc today but there hasnt been any odd smells to note.

Thanks for your reply

[Rikki]

kev b said:

Check the carpets, they may be damp through to the sound deadening if an over zealous valeter has soaked the carpets whilst shampooing them.

I am assuming you cannot smell antifreeze as a leaking heater will wet the interior and coat the glass inside.

Ill do this today.

No smell of anti freeze that I can detect and the car hasnt alerted me to being low on coolant - though Im not sure how to manually check the levels on the Cayman as it was visually easy on the Boxster (time to dig out the manual!).

Thanks

[Magic919]

They do the Cayman as a cab?

[996TT02]

Rikki said:

When I bought the car I turned the air con off - force of habit from ye old days of extra fuel consumption I suppose.

My previous car was a 2004 gen 1 Boxster S and I never ran the air con on it unless it was really hot and I didnt have the top down and I never saw anything like this with residue appearing on the glass and I ran that car for nearly 5 years.

Ill investigate carpets etc today but there hasnt been any odd smells to note.

Thanks for your reply

Probably this is it. Especially getting into the car with perhaps slightly humid clothes from the rain, the relative humidity will shoot up which is why your metal bits are rusting.

When you get out of the car and the heater is off, and the air inside cools, the RH increases even more and you get the condensation.

If you must leave the aircon off, at least get it back on again for the last 10 min of your journey to dry out the air.

[av185]

Good point......thought twas a Coxster for some reason....

[kev b]

If you don't run the air con then the seals may dry out and cause it to fail, this will cost way more to repair than any fuel savings you make.

Modern compressors sap far less power than those of days gone by, where the drag was so bad it might stall the engine when switched on at idle.

I have a pal with an air con business and leaking /seized compressors due to non use are a large part of his work.

[Rikki]

Thanks for the replies.

The rust and discolouration was there when I bought the car, as viewed in the dimly lit valeting bay they hid the car round the back in - but its only been in the last week Ive noticed the windows having residue building up. The first week was ok as the weather was brighter - still not running air con but this last week its been quite wet and Ive really noticed it.

Here is a better pic.



The rings at the far rear of the boot arent as tarnished as the ones on top or more towards the centre of the car.

The coolant level is sitting OVER the max level so dont think it is the heater matrix or the level would have dropped down - though it is worrying it is so high (this was after 12 hours of car not being used on flat ground). Least its the right colour.

The wetness around the edges of the trim in the pic above is where I used some Holts Rubber and Nylon lubricant on all the rubber seals around the rear hatch and the doors/windows.

No dampness on any of the carpets either, and last night was a down pour.

I did notice the rear hatch adjustment rubber screws were almost fully extended though so I've tightened them up into the hatch a few turns which might help make a better seal against the body work's rubber seal.

[Trev450]

Rikki said:

I did notice the rear hatch adjustment rubber screws were almost fully extended though so I've tightened them up into the hatch a few turns which might help make a better seal against the body work's rubber seal.

This has probably been done to help eliminate the dreaded Cayman tailgate creak which will usually only manifest itself when the weather is cold. Plenty on this if you do a search.

[Rockster]

Check the water drains located under the plastic panels on either side of the battery cover under the front trunk lid. While you report no sign of damp carpets -- did you give the floor under each seat a good feel for any signs of dampeness? -- if one of these drains is blocked it can allow water to accumulate and humidify the cabin air. The water hasn't overflowed, yet.

Not sure how to do this but you want to be sure the water drain of the pan under the A/C evaporator is free flowing. If this is blocked water can accumulate and this works also to humidify the cabin air.