Cool down
 

Just Curious. I am a new owner. 2002 35,000 miles Boxster. How long does it normally take for these engines to cool down after shut off. 70 degree day, car in the garage, etc. I actually drove the car 400 miles home after I bought it and what a fun car...no overheat issues, steady on the mark around the 180 on temp and also when I drive around town...gets up to that mark and stays. But seems the car take a while to cool down so just curious.

Driving long periods heats up all of the parts of the car (saturated heat sink) which requires a longer cool down than simply driving normally day to day. After four hours of driving it could take as much as six hours for the entire car to reach ambient temperature again. In normal conditions it should cool in two hours depending on ambient temperatures.

I am referring to the metal parts of the car. The temperature of the coolant is dependent on the total volume of the cooling system and the amount of surface area for heat to be exchanged across.

I have definitely come out to the car several hours later to still find heat coming off of the exhaust and out of the right side vent, long after driving. In the summer the car takes a really long time to cool because of the higher ambient temp, and doesn't take quite as long in the fall and winter. The engine bay does not really let go of heat all that easily, and you'll even feel the heat come through the material behind the seats during a drive.

That is exactly what I was referring to...right side vent, felt heat coming off for what seems to be at least 3-4 hours later. But I ran the car pretty hard!

The right vent is the cooling/exhaust vent for the engine bay. When you're driving it acts like ram air cooling, and when you're stuck in traffic and getting no air in there, a fan is there to push air out of it and get the engine bay temp down. It's completely normal for there to be heat coming out of there for hours after a drive. Even just driving the car for an hour I can find that area warm a few hours after parking it. It's only inconvenient in that I have to wait for the car to cool a good amount before I cover it back up so I don't melt parts of my car cover.