White steam from exhaust?

2017 AUDI A1
46,000 MILES • 1.0L • MANUAL
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JOSH HARRISON
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When I start my car there is thin white steam I think, coming from my exhaust, it sometimes stops after driving for a bit but sometimes after driving 30-40 minutes the steam is still noticeable especially when I rev the engine. Sometimes it completely stops, other times more steam than usual. When steam had stopped coming out once I smelled the exhaust and it smelled of chemicals almost like fuel, I’m not sure.
Jan 14, 2023 at 11:56 AM
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CARADIODOC
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If your exhaust system, catalytic converter in particular, is working properly, water vapor is one of the byproducts of burning gas. That can show up as a little steam, or water dripping from the tail pipe or a small hole at the bottom, rear of the muffler. That little steam is normal, and you will smell the chemicals.

What you want to watch for is a lot of white smoke, and the level drops in the coolant reservoir. That level will go up when the engine is warmed up, and it will be a lot lower when the engine is cold, but you should not need to add any. If that level remains in the same range, there's nothing to worry about.

If the coolant level does drop over days or weeks, it is usually caused by a leaking cylinder head gasket. Unfortunately that has become rather common since the late 1980s, but it is not a good suspect yet at the mileage you listed.

Here's a couple of articles you might want to take a look at:

https://www.2carpros.com/articles/how-to-check-engine-and-battery-pack-antifreeze-levels

https://www.2carpros.com/articles/white-smoke-or-steam-coming-from-the-exhaust-pipe
Jan 14, 2023 at 12:46 PM