water Interior water problem ( rear carpets )

[Douf]

Hi 

Can anyone help?   I have a 2006 IS250 and had no problems with the car during its first five years.  After that period of time i noticed that I had a condensation problem on occasions and noticed that the rear passenger carpet and mat was damp.  Thinking that I had left the window open or something similar, I dried it out and thought nothing more of it.  It happens a few more times and I took it to the dealer who tested the car for leaks.  None was found.  With me being retired and trying to save as much possible, I have had the air conditions switched off as i only take short journeys in the car. I have not had a problem regarding this for about three to four years.

Went on holiday with the car and have been doing some high mileage over the two weeks.  Had the air conditioning on due to the outside temperature being 25 degree.  Came back from holiday and noticed the windows steaming up that evening.  Next day I went to clean out the car and was vacuuming the rear area when i felt the rear carpet and it is soaked. Looked in my cleaner (which is now probably broken as water was  inside the motor). I took out the mats and water was dripping from them.  The two rear carpets are full of water.  We had no rain at all whilst on holiday.  The only difference has been the higher mileage and the air conditioning being on !!!

Has anyone else had this problem and know how to cure it?  Is it a design fault?

Thank you.

[madasahatter]

Can not see how air con is doing the damage. I would buy a smoke bomb set it off and if any leaks are evident you will see them.

It could be the boot that is leaking, have you checked the spare wheel well. Could be over flowing into the rear, is the carpet wet on the rear under the seats.

[is200 Newbie]

In the boot on the right hand side near the amp (if you have one although I think the vent will be there not matter what) there is a vent which I found a while ago. Not sure why its there but mine had a load of muck on it which to me suggested water could get in and out. Check to see if this is blocked or at least wet. Give it a clean eitherway. Not sure if there is another one on the left hand side but worth a look.

Another area to check, at least to rule it out, under the driver and passenger seats I am sure there are air ducts from the heating system, check to see if these are wet or dry.

[aly-g]

I have read somewhere that the drain off for the air conditioning can get blocked and this could cause the symptoms that you are getting, ie water inside the car, I believe the drain off is located in the transmission tunnel, along side the gearbox, I'll try to find the post that refers to this problem as I'm pretty sure this is your problem, hope you get it cured soon.

Allan

[aly-g]

Hi Steve, I have found the post on the USA Lexus club forums a common problem apparently ! If I've done this correctly here is the link https://www.clublexus.com/forums/gs-3rd-gen-2006-2011/694622-easy-fix-for-the-clogged-ac-drain.html  hope this helps. 

Allan

[Linas.P]

I as about to suggest AC drain as well, but the problem is that no matter how blocked it gets, you won't have a swimming pool on the rear carpers, more likely front passenger, but even that would be extreme. One way or another making sure all the drains are clean (including AC) is good maintenance. I liked "smoke bomb" suggestion for finding the leak, though if you don't have a sunroof I cannot think of any other leak (that is unless the car was damaged previously). So far AC drain blockage seems most realistic, especially as you stated you don't use it that often (still mystery how it got to the rear passenger carpets).

One other thing Steve... I appreciate you trying to save, but you kind of doing it wrong and risking expensive repair. AC has much bigger impact on small engine car e.g. 1.1 Fiesta and can add probably +20% consumption in standstill traffic. I have tried to measure fuel consumption on IS250 on AC on and off and could not find any meaningful difference, still I would agree that it is better to turn it off in a traffic jam, but otherwise (as long as you moving) it must be ON permanently, even in winter (or rather especially in winter). First of all whatever extra consumption AC adds it is not going to offset costs of replacing AC pump (£800-£1100). Now this is where it become important - coolant in AC system has lubricants and it must circulate otherwise AC pump (and other) seals gets dry and starts leaking ultimately resulting in system running dry and AC pump seizing. Additionally, if you keep AC unused for prolonged periods it allows for harmful germs and other filth to grown in your AC system, especially condenser - these not only stinks, but can as well be extremely harmful to your health. I often like to illustrate all this in a simple calculation:

Say you are doing 10000 miles per year, in a most extreme scenario where you all the time in standstill traffic AC would consume extra 5% (but more likely <1% on mixed) which would add 500 extra miles worth of consumption, so roughly 1,5 tank or about £100 per year. Now unless you assume you will have no problems with AC for 11 years can you break even. Not to mention a potential health hazard. To summarise - if you have AC in your car you should periodically use it, fist of all to maintain the system, secondly to prevent much accumulating in the air channels and lastly probably too dry out the interiour (after all AC not only cools, but as well drys the air). 

[dazed]

This ^^^^^^^^^^^

I too would recommend leaving the climate control system on at all times. As Linas says, the extra fuel consumption is negligible and it has the significant advantage of reducing the on going maintenance costs of keeping the AC system running smoothly.

[Linas.P]

btw sorry for poor English... I should drink my morning coffee before posting 

[peachy]

I always knew lexus made luxurious cars but a swimming pool in the rear is something else.

[Linas.P]

If you keep your AC off for long enough it might transform in something like this:

Just make sure you keep doors shut...