CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Water Leak

When it rains, the rear floor mats get soaked. The front and the truck remain dry. Where should I take the car to have it diagnosed and or repaired? In checking the interior, there are no obvious signs of a leak, yet the rear mats get wet whether the car is being driven in the rain or sitting still. The car has a sun roof.

What year 530i? You do say “the front and the truck” I really don’t know what that means.

The car is a 2003. The front floor mats and the truck mats to not become soaked. It is only the rear seat floor mats that get soaked.

I say the Dealer, second choice is a dedicated BMW Independant,last is someone totally inexperienced on this car. You need experience here. Sunroof drains or door seals are a possibility.

No technical service bulletins about any water leaks (I looked).

You were doing go to mention the sunroof. They have four drains and they often clog and when they clog they leak. My guess is it is a blocked sun roof drain. They can usually be cleared by using compressed air or string trimmer line. I generally recommend letting a professional do it. The idea is really simple and you likely do it, but if you put in a little too much enthusiasm, you could damage a drain or blow a connection apart making for a much more involved repair.

I had the same problem on a 2000 Blazer, front dry, back wet on the driver’s side only. There was a crack in the seam between the inner fender and the firewall.

I found the leak by running water into the windshield cowling and shining a flashlight under the dash. The water reflects the light. There was a stream of water running down the seam under the carpet and padding and then pooling in the rear seat area.