2006 Porsche Cayenne • 48,000 miles

Started my Porsche Cayenne S (06) today and it seemed having a little difficulty starting. Once it did start, it shook a little and almost rumbled. Never experienced that with it before, and it's very hard to explain. I shut it off instantly because I was scared to run it. After 10 more minutes I started it again, and it seemed to start a little more easy however it still shook a little. I opened the door and a smell hit me that I never smelled before. The smell didn't really smell like gas or oil, the smell was hard to explain and it was coming from the engine. I let the engine run and there was a silent ticking sound coming from the engine, I shut it off again, and didn't start it again. Does anyone know what is wrong? What do ya'll recommend me to do? Should I drive it to the dealership? I'm afraid to start it again.
September 2, 2012.

The information provided is not sufficient for us to understand what could be wrong. It wuold be best to get someone to have a look at it.

Sep 2, 2012.