The engine in my 2002 Holden Commodore will stop for no reason. When I take it to the mechanic he can't find anything wrong. If I let it sit for around 10 minutes, it will restart but it is happening more frequently. What could be the problem here?
Based on the symptoms, it sounds like something is getting hot and shutting down. When you leave it to cool for those 10 minutes, it fires up again. This could be something in the ignition system becoming too hot, or the fuel system (fuel pump) or perhaps even fuel vaporisation.
However, the V6 engine in your Commodore is very well known – notorious, even – for a crank-angle sensor that can stop working when it becomes too hot. This is a condition that seems to set in with age and, as the sensor becomes less tolerant of heat, will simply shut own the engine with no warning. Here’s something to try next time it happens: Identify the sensor in question (it’s located down by the front pulley of the engine’s crankshaft. Keep a bottle of tap-water in the car boot. When the engine stops next time, open the bonnet and pour the cool water on to the sensor. In many cases, the water is enough to cool the sensor and the engine starts right up. Definitely worth a shot before you start replacing other bits and pieces.