Your Car: Ensure your scuttle drains are clear

By The Helpful Engineer / On / In Technical & Discussion

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.

1. Windscreen drain
2. View of blocked scuttle drain
3. View of scuttle drain in engine bay
4. View of removed scuttle drain


15 thoughts on “Your Car: Ensure your scuttle drains are clear

    1. i had a problem with blocked scuttle valve , i cured this by pouring pedal bike cleaner fluid neat onto the scuttle tray which then flowed down to the valve, waited about half an hour then washed out with warm water, this seemed to do the trick , would recommend doing this once a month

  1. Thanks for the info. My problem is water collection in the trunk of my BMW hardtop convertible. Any idea about where to get a schematic of the drain system on various cars?

    1. G,day and thanks for the input! I have this ongoing problem. I have replaced the pollen filter and put scuttle panel back. I am still getting water in. Exactly, where are the drain holes, there are about six on each side. Which one am I looking to clear? The picture showing the cable, is that the hood release cable, just so I can work out the vicinity of where to start. My original problem was in fact, the heater core, which cost $4000 as they have to pull the entire dash out. That,s fine but this other is driving me crazy! A closer picture would help! Thanks!!

  2. thnks – I have 2006 c280 and it fills with water when it rains heavy – I checked drains on windshield and found 1 clogged but yet to remove battery to check that drain – thanks for info..

  3. Any ideas on how much it will cost to get a garage to clear out the scuttle drains? I’d do it myself but it needs to be done asap, I don’t have access to any overhead cover, and it’s set to rain for the whole week (like literally non-stop rain). Thanks.

    1. I dunno if conversion works but my friend who had this problem few weeks back (that led me to self check my own car gutter system) paid only about $16 or $20 (converted from local currency) for a home service from car brand distributor service. (Mine is a Toyota) I understand he made a prior booking. Am trying to do the job today that lead me to this site, with few tools on my hand I guess i have to make a call asap.

  4. It will be nice if to have a small tube or a compressor tube to blast the dirty air through the drain pipes also no suction hoover with a very thin nozzle will be ideal

  5. I have said in so many places at so many website didn’t find anything also I looked into Ford manual to see nothing at all thanks to you guys I can see see what you’re talking about

  6. I am having a problem trying to find why I am getting water in my drivers side back footwell taken the car back to audi hyde who told me I needed a new air con switch as they had previously replaced the air conditioning pipe 18mths earlier having had the same problem. The car is completely dry apart from this, can’t seem to get this problem fixed by anyone very frustrating

  7. I have water coming in the back panel behind drivers seat it is a renault wind think it could be drainage problems but don’t know where the drains are

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