Earlier, water like drops come out of the exhaust of my car. I searched web, and it shows that its a good sign. But for last few months after a regular maintenance cycle (Oil, Oil Filter, Air Filter, Air Conditioner Air Filter etc), it stops. Is this a bad sign or this is perfectly normal?

Edit: I don't know, if this help anyone or not but doing a general service of entire car including washing of sensors, did the magic. The behaviour comes back. The reason my local mechanic told me was it was due to some sensor not reading proper signals out of something. Although, I didn't buy his argument - but that's what it is. Thanks everyone for answering.


It means you have probably driven short(<10km) trips. The exhaust doesn't get the time to get hot then, so the water vapour in your exhaustgases condensate in your exhaust. That's also the water that's coming out of your exhaust. If you don't make a longer trip every now and then, the exhaust never gets hot, and water builds up in your exhaust dampers, making them rust much faster. You can drill small holes(1mm) in your dampers to drain the water and prevent this, but depending on your country it are it may not pass the MOT anymore.

  • "drill small holes(1mm)" Please, no one ever do this. You're breaking stuff to fix problems that aren't problems. – justinm410 Nov 14 '16 at 19:25
  • @justinm410 If you want to replace your exhaust twice as often, you shouldn't do it. If you want to save money, and the MOT in your country doesn't care about it, you should definitely do it. If you drive short trips, especially in colder and humid countries(like the netherlands where i live), it greatly extends the life of your exhaust. Because of their tiny size, those drain holes won't have other negative effects. You're not 'breaking' it. – Bart Nov 14 '16 at 20:29
  • How many times are you replacing your exhaust?? If your exhaust is rusting out and you are having to replace cats regularly, then you're doing something different than the rest of us. – justinm410 Nov 14 '16 at 20:54
  • @justinm410 I don't have a cat in my exhaust(oldtimer) but the especially the dampers rust after a certain time. Without a little hole they last around 6 years and with them they last 12 to 16 or so. Talking about stainless steel exhausts. Remember it depends heavily on the climate in your country. A humid cold climate nearby sea is the worst. In warmer dryer climates it's less of a problem. – Bart Nov 15 '16 at 10:41
  • I take it back. I work on perfeormance cars made mostly in the last decade and exhausts and cats should last the life of the vehicle. I think I had in mind people punching holes up through the exhaust of their 2016 Honda Odyssey ;) – justinm410 Nov 15 '16 at 13:59

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