Steamy Windows

[Enda]

Hello again just wondered if anyone is having problems with the windows steaming up when it is warm and wet outside.

I have to keep the windscreen demister on full power all the time to enable me to see out when the weather is like this.

Never had this problem with my 3 series bmw or any other car and wondered why it was happening with the Lexus.

[F.A.]

Windows steaming up when it is wet outside is often a sign of water pooling somewhere inside. This could be damp mats from wet feet or more likely a leak somewhere. I have only heard of the 2nd gen IS leaking in the boot due to a bad accident repair though, but I am sure someone will correct me if i'm wrong

[colbecoz]

I was told that you can get water pooling under where the windscreen wipers are, and this causes steaming up. It can also happen when you have had the airco on and then switch it off. I think that's why Lexus designed in the front window demist boost???? I may be wrong though. Matus usually has an answer for these type of queries, so, I hope he responds. ( It happems in my o8 Lexus).

Col <[;o)

Windows steaming up when it is wet outside is often a sign of water pooling somewhere inside. This could be damp mats from wet feet or more likely a leak somewhere. I have only heard of the 2nd gen IS leaking in the boot due to a bad accident repair though, but I am sure someone will correct me if i'm wrong

[Tango]

Never experienced it with either the IS250 or the IS-F. You may want to check that the air outlets to the cabin are clear so you get a good flow through, or any water brought into the car by wet clothes, feet or just from the drips you get when opening the door will just keep circulating. Always presuming of course that you have the air conditioning system on flow through, as opposed to recirculate.

[Skidspan]

Hi Enda,

It does'nt sound right if you are unable to defog the windows after a short while. I think Tango touched on the possibility of wet damp items. I have seen this before on a number of cars and it's always wet damp carpets inside the cabin, the most likely cause is the air conditioning drain pipe kinked or dis lodged. The air condition unit drains a lot of water from under the passenger side of the dash through a plastic drain pipe down through the passenger footwell onto the ground. If this pipe is kinked, plugged or disloged the drain will overflow at times. The carpets normally scok it up underneath the passenger carpets. so get right at the back of the footwell carpet and try pull it back a little and with your hand you should feel wet or dampness. It should be bone dry.

It's normally a simple job no tools required. Locate the drain pipe and examine

hope this helps.

[Shepherd]

do also make sure that you turn on AC at all times. it does actually helps remove the mist from screen and moisture from car

[Enda]

Thanks for the replys everyone will give the car a check now.

[fjcfarrar]

Thanks for the replys everyone will give the car a check now.

This is particularly likely to happen this time of year if you have parked where the sun shines for part of the time and evenings are quite cool. Any residual moisture (which is inevitable) in carpets, seats, trims etc. is vapourised by the heat from the sunshine, and when the car falls into shadow, the windscreen rapidly cools and the vapour condenses on it. You then come out to a car with the windows already steamed up. If it still dry weather, turn on A/C, screen-blower at full tilt and drive off with windows open. If it is damp, don't open the windows. The effect is worse with today's heavily raked windscreens than when they were more upright.

[Enda]

Well i have checked the car for leaks and wet carpets but found nothing.As the above post suggests it might well be the humid and wet climate at the moment as it only happens every now and then.

Thanks

[Steve]

keeping the AC on all times stops the misting.. never once had misting with it on.

[Cue]

keeping the AC on all times stops the misting.. never once had misting with it on.

It's not really helpful when it's cold conditions and your expected to use the aircon whilst freezing in the car...?

[Shepherd]

The way I see it, having AC light on in the button doesn't really mean the AC is cooling the car. It means that if the car gets too warm, the AC will help bring it back into your desired temperature. Otherwise the climate control will not works as the heater will be able to warm the car but if it heats it too much it cant cool it. I have the AC button on all the time, no mist ever and no feeling frozen inside the car as well. I think its just designed to be ON all the time.

[hooba]

i also have this problem with my 56 IS, surely u shouldnt have to constantly have the AC on to keep the windows from steaming up , i have checked for damp and found nothing, is it still possible there could be a problem with the AC and is this jus a problem with a few cars or every IS of this age?

[Skidspan]

Hi Guy's

This is an interesting topic, and a lot of folks miss understand the function of the AC in winter. The AC will cool the cabin temperature to the desired level during hot weather. However AC can be used all year round even in frigid conditions! It's not used to keep the temparture cool if it gets too hot, the cars automatic climate control will do that job on it's own. The function of the AC in winter time it to act as a kind of hudmidifer/ cleaner/ fresher/softer air inside the cabin as it works in conjuction with the heater. Without AC on in the winter the cabin tempature is very dry and uncomfortable. You all know what I mean, dry lips, tired eyes stuffy. Well the AC left on with the tempature set to warm or very warm will ensure the air quality is pleasant. So keep AC on and adjust the temparture to the level you want. To prevent misty windows make sure the temp control is NOT set to recirculate air !! This will fog up windows very quickly. remember at certain times windows will fog up but you should be able to clear this with setting the temp controls.

I hope this helps

Regards

Skidspan B)

[steve2006]

AC systems not only cool the air they also dry the air, hence why they have a receiver/dryer so leaving the AC on will remove moisture.

Other things to check are a build up of debris especially leaves in the air intake vents across the rear of the engine bay, this not only affects circulation but if the debris is wet this moisture will be sucked in through the vents.

Also make sure your cabin pollen filter is clean and serviceable.

[nottonto]

Hi

here's my two-penneth....is your ventilation control on recirculate ?, fresh air from outside helps stop misting

[corglass]

Guys,

Just to even things up.

I've an Is220d, here in Ireland with 245,000 km and only had the following issues:

- 2 x front suspension

- needed new drivers mat, cos my foot eventually wore a hole in it.

:)

Oh, and I'm getting 38-45 mpg. Happy out. Love the car.

[steve"o"]

Hello again just wondered if anyone is having problems with the windows steaming up when it is warm and wet outside.

I have to keep the windscreen demister on full power all the time to enable me to see out when the weather is like this.

Never had this problem with my 3 series bmw or any other car and wondered why it was happening with the Lexus.

hello my name is steve.

I have the same issue and after a while i noticed that the air intake button on the dash always defaults to recirculate,i have found when you select the air from outside this cures the problem,i have asked lexus about this and they say the air intake button always defaults to recirculate,hope this cures you issue?