Water vapor from exhaust

[chucklong]

I just bought a 2008 Cayenne S with 25k miles and factory warranty. I learned a lot about what to look for here on this forum, thank you. When driving my Cayenne in the cold weather of Washington DC, enormous amounts of water vapor come out of the exhaust pipes when the vehicle is cold and even when it is warmed up to operating temp. I had the dealer look at and they replaced the fuel pump under a recent recall and the truck still does it. I know the science behind why water vapor occurs, but once the exhaust is hot it usually goes away. Does the design the the Cayenne exhaust make this vehicle prone to doing this? It runs great otherwise, I am impressed.

[odix]

Hi chucklong --- welcome to Renntech.org, glad it's been a helpful resource. Consider becoming a contributing member, it's the best $25 I ever spent for my Cayenne S ('04). And I actually contributed an additional $25 I was so impressed with the site, Loren and other members. It's an amazing community.

To your exhaust vapor question -- DC is a humid area, not sure if that has something to do with your issue. Upon start-up and for a few miles I see vapor as well. Have you been on a long extended high-speed drive yet? I drove from San Francisco to Los Angeles and back a few weeks ago (the Cayenne is a great road-trip vehicle). Temps ranged from mid 30's (F) to 70's. In California the highest octane gas I can usually purchase is 91 (Shell). Vapor emissions in the beginning of trip/cold engine, was normal, once underway no more vapor, even after stopping to fuel-up in the mountains at night in the cold but the vehicle was quite warm at that point.

I see many types of Cayennes's around in California and have not noticed an undue amount of vapor emitting from their exhausts relative to other vehicles. But I have not observed Cayenne's in cooler more humid locations. Although recently in Tahoe (high elevation) in very cold weather I saw a few Cayennes and Touaregs and none had undue vapor emissions but again, that's a high desert, low humidity type of locale. My Cayenne has more initial vapor than other vehicles I've owned (Subaru's, VW's, etc.) but it has a larger displacement engine than vehicles I've owned in the past.

And in a very recent discussion in this forum RFM (he's a a classic example of how knowledgeable and professional Renntech members are) noted, "...remember that a cold engine gets soaking wet inside until fully warmed up (approx. 10 to 15 Km normal driving). This is therefore a normal phenomenon."

Oil Leak Over Intake Pipes

Congratulas on your Cayenne and keep us posted on your findings!

[mudman2]

up in Philly when its very cold its amazing when I floor it, the rear window becomes a white out

[rizzo]

Is that some sort of James Bond option we're hearing the first of? VIN number option code please?:drive::cheers:

up in Philly when its very cold its amazing when I floor it, the rear window becomes a white out

[mudman2]

007 of course

[KhmerPepperS]

I also am in the cold Philly area and when I gun it it looks like I hit the smoke-screen button like the classic Spy Hunter game.