Looking to purchase a 2007 Limited Roadster with 77k miles. Very honest owner said white smoke came out of exhaust for a few minutes when he started it up that day, and that was the first time it had happened. Described it as looking like steam from boiling water. Ambient temperature was around 90 degrees. He had called me on my way down to tell me this so I would not waste my time. It was an hour and fifteen minute drive When I got there, he started it up and no smoke. Took it for a 10 minute test drive and no smoke. Said he had started it a few days earlier with no problem. Prior to that, it had sat a week. Head gasket or condensation? If blown head gasket, how long would one have to drive it before the coolant level would start to drop? What other tests or procedures would help to determine status of head gasket?
Pete Jones
Manassas, Virginia

 

Yank the dipstick out, if there is coolant in the oil, it will be obvious.

We had a bad head gasket in a Pontiac 35 years ago and the dipstick looked like there was mayo in the oil.
Sounds to me like you just had condensation in the exhaust system. Deb Walker started her coupe up cold one morning and took off ahead of me, she sprayed steam all over behind her.

 

There were no fault codes on my WiFi OBD scanner if that makes any difference. I've got OBD Fusion software on my IPhone.

 

I work for a car lot here in Louisiana, we have a lot of different types of vehicles, even German vehicles. I have noticed this when we start one that hasn't been run in a while, seems like steam. What's happening is when the morning moisture sits in the exhaust piping, then the vehicle is started and the piping heats up, it boils off the water sitting in the exhaust.

 

Thus stainless steel exhaust systems.
I remember a 1986 Olds my mother had that she drove about once a week and then not far enough to get up to operating temperature.
I replaced the exhaust pipes and mufflers on that one 3 times during the 7 years she owned it.