One problem related to engine failure has been reported for the 2004 Porsche Cayenne. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Porsche Cayenne based on all problems reported for the 2004 Cayenne.
Coolant line/plastic coolant hose failure. I was driving in traffic and my low coolant light appeared. Within seconds, the car began smoking and the temp. Gage rapidly began to rise. I had to turn the car off immediately in the middle of traffic to avoid possible engine failure. I towed the car to my mechanic and he indicated its a design defect from Porsche and the plastic tubes are now replaced by orem aluminum tubes. Upon further investigation, I was able to determine that the design flaw by Porsche was concealed. The Cayenne s is in the shop and I'm hoping that only the hoses need replacement and nothing else was damaged due to this issue. A huge dent in the wallet as this is a costly fix.