Hi,
Porsche acknowledges that the Boxster can experience problems with rain entering the Engine through the Air Intake. They released a TSB - 7a/97 2425 on it as well as a modification to the Air Box. In it they state:
- "Concern: Water entering the left-hand air guide and air cleaner housing.
Situation: Engine misfires during driving, rough running, poor starting.
Information: Water can enter the air cleaner housing via the air guide when
the vehicle is driven in unfavorable weather conditions, e.g. during rainstorms. This can cause engine misfires and rough running. These problems do not necessarily occur during these weather conditions; they could show up later on. Please ask the customer if the vehicle was driven in these weather conditions.
Modification:
1. A gasket between the outer left air guide and the body seals out water.
2. A deflector is fitted on the air cleaner intake opening, and a water separator bowl is fitted on the air cleaner housing.
3. The formerly used water shield support in the flow
duct has been omitted."
I suspect this is what has happened to your Car. My wife (Mrs. MNBoxster) is in New York this week for the Barclay's Golf Tournament and when I spoke with her last night she said the rain came down in torrents.
It should dry out and function normally. If a huge amount of water was injested, there could be more serious issues, so I would have the Car checked and I would look into having the modification performed. Hope this helps...
Happy Motoring!... Jim'99