Kalspeed

Yesterday ( and early today) we received quite a bit of rain, as well we have the normal humidity in our region.

I made the mistake of keeping the 928 outside at a different location, didn't expect the sudden rain, anyways

Looking at the video below, is this normal or excessive, or is a sign of an exhaust leak. I noticed on normal days, on occasion, I would see a minor water leak under the front exhaust.

http://youtu.be/uIyzReh6Kz8

Avar928

https://rennlist.com/rennforums/showthread.php?t=593570

I found this thread which may be of help.

SMTCapeCod

Cold metal and the dew point are key to condensation. Precipitation shouldn't do much noticeable.
It's a bit, but I wouldn't be too concerned..there is a lot of surface area inside of the cats if the condensation is at play. If the problem were head gasket/coolant related- there is often a smell that is discernable and the steam persists to a greater degree than just water.

Mrmerlin

after starting the car smell the exhaust,
if it smells sweet then pull the plugs
and see if any are very clean or might have rusty tips,
if so then you have coolant leak.

From what i saw it looks normal
IE no issues other than possibly not driving the car enough

Kalspeed

Thanks, interesting thread, makes sense.

I don't drive her that often, maybe once or twice a week.....40 miles max one way.

Kalspeed

Yeah no coolant issues, I don't drive her enough, and recent rains reduce the driving time even more.

Thanks, was a bit concerned from the intensity.

Bill Ball

There's your problem. Mine never has time to form condensation.

Combustion generates H2O. So, water vapor spitting from the pipe initially is normal. As the exhaust heats up, this evaporates before it gets to the end of the tailpipe.

Also, it looks like your exhaust is perhaps tilted slightly up at the end. Since this happened after a bad rain, that may be a factor.

Kalspeed

The exhaust angle seems ok but I have nothing here locally to make a comparison.

I think tomorrow I should drive her for an extended period, beyond the 40 miles.

May be a good exercise to perhaps present others issues which I am unaware of.

thanks all

17prospective buyer

Give it an italian tune up, seriously. A long trip would probably be good for it. Blowby contaminates oil with lots of water and toxic products. If the engine never gets up to spec operating temp, those things never get a chance to exit through the PCV valve as vapors. Here at the shop in college all the cars we work on have very very diluted oil due to not being driven beyond the shop car parking lot. Water of course sinks to the bottom of the oil pan.

NoVector

+1 I think the same thing when people see a little white foam on the dip stick or under the oil cap.

WallyP

Burning gasoline generates just over one gallon of water for each gallon of gasoline burned. This can cause several results.

Hard starting, especially with dirty spark plugs. It is possible, especially in colder weather, to have moisture condense on the cold spark plug insulators inside the combustion chamber on the first few cylinder firings. This can be enough to cause the voltage to follow the moisture from the enter electrode to the body of the plug, rather than jumping the gap. This condition usually lasts only a few seconds of running.

Moisture in the oil. Almost all of the moisture generated goes out the exhaust, but the blow-by that gets past the rings and exhaust valve stems dumps the moisture into the crankcase, where it condenses and ends up in the oil. You need to get the oil and the crankcase hot enough to vaporize the moisture and get it out. (This situation led to the old urban myth that cars used more oil on a trip than around town. Short trips put enough moisture in the oil to make up for the oil that was being used. When you put the car on the road, the oil finally got hot enough to drive the moisture out of the oil, and it looked like oil consumption had increased.)

The invisible water vapor from the engine condenses in the cold exhaust system into visible fog and water droplets. This is what you show in your video. The very high moisture content in the air going into the engine adds to the situation. 100% humidity at warm Florida temps is a lot more absolute moisture than 100% at cooler temps.

If you really want to get into trouble, rev a cold engine just as your wife or SO walks by the tailpipe in white pants...