Roughly a year ago I discovered a large amount of water was lying in the foot wells of my car. I had no idea what was causing this. There were no obvious problems like a leaking radiator. After a long time I finally discovered it was a blocked scuttle, or windscreen, drain. If the scuttle drains block the water can backup and enter the cars interior through the air intakes. It took me along time to get the car dry again as the sound proofing material used under the carpet can absorb a lot of water and is hard to dry. Therefore it is essential to keep these drains running freely because they are rarely checked or cleaned as part of a car service. What follows is some information and tips on car scuttle drains, with photographs also:
What is a scuttle drain? A scuttle drain is used to divert any water which falls on your car windscreen to the ground, without coming into contact with your engine or exposed metal. When water falls onto a car windscreen it runs down the face of the glass and is diverted though drainage holes onto a covered collector gutter below. The water drains through holes on either side of this gutter and is then diverted through rubber scuttle drainage pipes which direct the water onto the ground below the car without any splashing onto engine parts, metal or wires. There are usually two, on either side of the car.
How do they get blocked? The dirt and leaves that fall onto the windscreen can block the drains. Like most people I had never cleaned mine and it took a few years for them to become blocked. If the car is parked under trees I would imagine it would be more likely that these drains would block.
How can they be cleaned? The drains are located in a difficult to access area at the back of the engine. The plastic panel at the base of the windscreen usually has to be removed to access the top of the drains. The drains can then be cleaned out using a flexible wire and flushed with warm water. Personally however I would ask your mechanic to do it during the next service. As a precaution the car user should remove any visible leaves and dirt on a daily basis from the base of the windscreen before it is washed into the gutter below.