Moisture Under Carpet And Mat On Passenger Side.

[Larry Robert Atwell]

Several months ago, I noticed that my 2001 RX 300's passenger floor mat was damp. After further investigation, I noticed the carpet was wet along with the mat and insulation underneath down to the metal. I had it examined and tested for leaks by my local mechanic and he could not find any where the water could be coming in. It got damp again and I would air it out. It appeared to quit presenting the problem, till I noticed a blackish substance on the carpet near the seat and rim of the floor mat. The floor and all material is wet including the matting going up the slant above where you would place your feet. Has anyone else had that problem and if so what was most likely the cause of the problem and possible solutions. thanks in advance

[1990LS400]

A common cause of a problem like that is a clogged HVAC drain tube. I haven't had it on a Lexus but I sure have on other makes. The way I have solved it is the pull the tube up out of where it runs through the floor and then to gently ream the tube out with a flexible small rod. The attached diagram has an arrow pointing at the HVAC drain tube. But of course, the problem could be caused by something else such as a clogged sunroof drain tube - see the second diagram below..

[pj8708]

Along with Jim"s explanation is the possibility of clogged drain tubes around the sun roof. In some models these empty toward the lower front

This has come up before so just do a search of the data base and you should find more innformation.