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Exhaust leak - just condensation?

Hi everyone,

I just went out to clear the snow and ice off my car and let it run for a bit. While I was brushing, I noticed a bit more exhaust vapors than normal…not really a big deal to me, as the car usually belches out a lot of vapors when it is cold. I did, however, notice a small column of vapors UNDER the car, from around the area of the catalytic converter (I THINK). Again, not TOO surprising to me, as I know the exhaust is sagging a bit and is in need of repair (just don’t have 1000$ to drop right now on a car that I don’t drive too often). When I crouched down to get a better look a minute later, I noticed that the spot on the exhaust where the column of vapor had been coming from was now leaking water. This is a new one. I figured it was just condensation - hot air meeting very cold air, after all - but wanted to make sure. Is this a sign of dangerous things to come? Could it be possible to have the exhaust welded up as a temporary fix?

Here is a lower quality picture of the leak for reference.

You have a hole in the exhaust system, from what you say. There is a lot of water in the exhaust, as CO2 and water are the two main products of combustion. So there is nothing unusual about water coming out of the hole, and it could be in the form of steam, or liquid.

edit: just saw the photo. That water seems to be coming from the body metal, not the exhaust, tho it’s difficult to tell… Edit2: now I think that is just an icicle in the foreground, not a stream of water.

Thanks for your reply, Bill. Makes sense that there is a hole in the system - it has been sagging for some time and it gets exposed to quite a deal of salt (so I imagine rust is rotting it away). I plan on replacing the whole system in the spring, but I want to make sure that I’m not playing with fire until then.

@BillRussell I agree. You cannot really fix a rusty exhaust system. Some auto shops sell temporary sleeves with straps you can wrap around a leaky muffler. Most people get it fixed or just keep driving until the pipe falls off.

I’d try the sleeve, but don’t worry about the liquid coming out of the muffler; its; the stuff that corrodes it over time.

One gallon of gasoline creates one gallon of water!!! Basic chemistry. When the car is hot this will come out as vapor; during warmup it will come out as steam and/or droplets of water.

The photo is low quality and I was at a bad angle (trying to avoid crouching in ice and snow on a cold day!). From what I could tell, the steam/water leak was definitely from the exhaust system (was coming from what I THINK is the catalytic converter, but I’m not sure about the anatomy of the exhaust system). No leaks from the body of the car that I could tell.

I would have to agree with @BillRussell s edits. I don’t see any evidence of a problem with the exhaust. The icicle appears to be hanging off the floor pan.

My 2 Cents - apologies! The ice cycle was just frozen from last time the water melted off the roof. Should have broken it off to avoid having that be central to the picture. The puddle under the exhaust system is what I was trying to focus on.

Parts stores also sell muffler repair kits that consist of a cloth-like fabric and a putty-on, self hardening “liquid metal”. It works great, I’ve used it, but it should only be considered a temporary patch. Rot spreads… the patch doesn’t! :smile:

I really think your only problem is that the warm exhaust is melting ice and snow from near the exhaust, and it is dripping on the ground under thew car.
Normally from an exhaust leak… with that distance to the ground…it would be more of a mist spread around the ground. Though I could be wrong.


One of the experts here have said, and I think it is a good idea, with this problem to get someone behind the car partially obstructing the tail pipe with a piece of wood for example. The another person crawl underneath and looks at the exhaust system. The way it works apparently, partially obstructing the tailpipe will force more exhaust gasses out any holes in the exhaust system, making any leaks easier to see. Worth a try to improve the diagnosis anyway. All exhaust system safety cautions apply of course.