Help identifying what appears to be a fluid leak

[fjordexpedition]

Over the past month or so, I began to notice black spots on the driveway where the Expedition is parked. Given that the vehicle is a '21, the last thing I am expecting right now are oil leaks. I thought that maybe it was just the AC drain picking up some dirt on the way to the ground and did not investigate for a while. Today I decided to take a look as the spot appear to be getting larger, and thought it looked like far too dark to just be some dirty water.

After crawling under the vehicle, I see that an oil like substance is collecting along part of the exhaust, and I assume this is the culprit based on the location of the spots on the ground. The picture is looking to the rear of the vehicle. Any idea where this fluid would be coming from? The vehicle sits at an angle on the driveway, and it seems whatever it is, is either coming directly out of the muffler, or else dripping from above, pooling at the bottom of it, and then running back and dripping off. I am taking the vehicle in to be looked at on Tuesday, but would like to try to gain a little knowledge of what may be going on before I take the vehicle in.

 

[Rob6805]

Exhaust condensation. Do you do mostly short trips? If so, you are never getting the engine and exhaust up to temp to burn off the water condensation. Depending on outside temp, you will get moisture in the exhaust stream normally too. It's black because of course the exhaust is dirty.

 

[Going_Going_Gone]

Looks like condensation draining out of the muffler. Generally caused by short trips that do not get the exhaust components warm enough to keep the moisture (by-product of combustion) vaporized all the way out the tailpipe. The black would be soot and/or other solid by-products of combustion.

 

[fjordexpedition]

Thanks for the replies. This vehicle definitely does do plenty of short trips when not being used for long road trips, like run the kids down the road to school. (I know this is terrible for a vehicle). I do agree, this looks like soot that I would find on the exhaust tips being mixed with water, but I am just thrown off by the location of it. Is it normal for this to be exiting the exhaust in those locations, rather than the tailpipe?

 

[Rob6805]

Thanks for the replies. This vehicle definitely does do plenty of short trips when not being used for long road trips, like run the kids down the road to school. (I know this is terrible for a vehicle). I do agree, this looks like soot that I would find on the exhaust tips being mixed with water, but I am just thrown off by the location of it. Is it normal for this to be exiting the exhaust in those locations, rather than the tailpipe?

Yes. There are build in drains (holes) in the muffler so water can escape. If there weren't it would rust out from the inside in no time. And where the exhaust pipe sections are clamped together that is not a water tight seal so you will get dripping from those points too.

 

[fjordexpedition]

That makes sense. I went out and wiped the collected soot off, and will try to make sure the vehicle gets up to full operating temp more often. I have plenty of experience with exhaust soot from turbo / DI vehicles, but I have never seen evidence of it from places other than the exhaust tips themselves.

 

[fjordexpedition]

As another follow up, I went out and started the car up and moved it to the other side of the driveway so that I could scrub off the soot. While it was idling, I could see the water coming out of the tailpipe and that mid muffler, a pretty good stream. I then took the vehicle for a drive to get it fully warmed up, and was surprised how long it took to get it to full operating temperature (it was 65F outside, so not exactly cold). I really only ever drive it on long road trips, otherwise it is just my wife shuttling around town. I would guess a majority of her trips it never even gets to full operating temperature.