Excessive Condensation In The Cabin

[KY350]

Well its summer here in Sydney at the moment and that means hot and humid days and occasional thunder storms.

My car is almost always parked in a garage when not being driven, except for last week when I picked the car up from the panel beaters. It was a very hot day and we had a massive downpoor, so when I went to pick up the car which was parked out in the rain, all the windows were covered in condensation. It took about 6-7min of driving with the AC on high to get rid of most of the condensation.

Then a few days later, my sister in law whom I lent the car to told me that the car had a condensation problem after another storm, while parked outside. She also said that the rear left passanger mat had a lot of moisture on the plastic underside. All the other mats were dry?

I am wondering what cause the massive condensation build up?

Perhaps it has to do with the mats which I washed approximately 2 weeks ago. I let them dry for 2 days before puting them back in the car. They felt dry to touch at the time. Perhaps they were not completely dry and had retained some moisture and are the reason for the condensation? But why would only one mat have moisture on the plastic backing and not all mats if the mats are the cause of the condensation. Or is there some other cause for the condensation? Has anyone else had any similar experience?

[VBdenny]

Sounds like either the heater core has a leak or your windshiled has a leak. When a heater core starts leaking the first thing you notice is condensation on the glass, then it gets worse. Windshiled leaks usually appear under floor mats.

[KY350]

VB - where do I start looking for a heater core leak?

[KY350]

I washed the car today and noticed condensation build up on the rear left window. Now I suspect that my problem may be that the seals are not working properly. They do however look fine?

Is it possible to replace the seals around the doors?

[RFeldes]

I would try silicone spray first. Which would make the seal more pliable. I would do all the seals on all the doors and I do it annually as preventative maintenance. If that fails you should go to a body shop and have the seal replaced or if you are handy or know someone who is, order it from Lexus.

[KY350]

RFeldes - If I understand you correctly, you're saying that my seals are firm and therefore not contorting enough to provide a good seal to prevent water penetration and silicone spray should soften them up for a better seal?

I do not recall the seals being firm, but I will check tomorrow when it is light outside.

Maybe a full replacement of seals will be necessary - i'll speak to my mechanic about this next service.

Thank you for your response. It's nice to be reassured that the seals can be replaced if need be.

KY

[RFeldes]

KY350- Yes, your assumptions are somewhat correct. They more than likely will feel soft as they are Lexus quality but I have found that a treatment will dampen wind noise as well. That tells me that after 14 or so years they need rejuvenation and also the silicone helps to repel moisture. You could have developed a pinhole which would be difficult for the naked eye or a slight tear from the bonding. Good Luck.