Sometimes my car doesn't start

I have a 2003 VW Passat 1.8L Turbo w/ 98,000 miles. For the past week or so, every 3 or 4 days, the car decides it doesn’t want to start. It turns completely over, the battery power is not weak, it just won’t start. If I let it sit for a few minutes (5 or 10), it starts up without an issue and the check engine light doesn’t come on. My last tune up was at 75,000 miles, when I also got new engine coils. I’ve had the timing belt replaced recently as well.

Since I can’t get the car to do this in the presence of a mechanic, (or anyone else for that matter) i’m at a loss as to what to do to remedy this… as is the mechanic.

Has anyone experienced a similar problem? Does anyone know what may be going on?

Has anyone dumped error codes out of the computer? They are pretty comprehensive — it’s hard to imagine this problem would not be generating a bunch of them. Error codes do not necessarily light the check engine light. There are places that will do this free, mostly auto parts stores.

For example, a routine check on my 03 Passat indicated that the sensor that reads coolant temp was bad, which could result in difficult starting.

I had the error codes dumped when I took it to the shop, there were none. I had my cooling temp sensor replaced 2 weeks ago, before the problem started & coincidentally, on the same day that I got a letter from VW extending the warranty on it.