[NWOrphan]

I have owned 3 BMWs: 02 325i, 06 330i (basic model) and the car I have now which is an 06 330i with the computer in the dash. I have always noticed working on the cars that every so often it sounds like the fuel pump primes, like the car constantly monitors the fuel pressure and keeps it from ever getting low; at least that it what it sounds like. Out of the 3 cars, this one is the only one I've ever had an issue with so it makes me think something else is wrong.

I just bought the car 5 months ago and now that it is cold the issue has shown itself. It had a new looking BMW brand battery in it but on the 15 degree mornings, I would have to press the start button 3 times before it would finally start. The battery seemed like it had plenty of juice to keep starting it, it just seemed like it had low CCA, so I went and bought a new battery after work (when it was 45 degrees and the car started just fine) after buying the battery, car started fine and I went and replaced it at home. The first start on the new battery felt no better than the start after work and after the store. if something was wrong with old battery at all, I would feel a difference.

So at this point; I was hyper focused on everything every time I got in the car and what I started to notice was, even on the 45degree mornings, it was doing it with the new battery. If I drove it once the battery would gain all it's cca's back and that is why the car starts fine the rest of the day, because it still has the fresh charge from the alternator.

At this point I believe something is causing my fuel pump to prime itself a lot more than normal and it is draining my battery more than it should over long periods of time. So now I'm starting to think that I have something causing me to loose fuel pressure faster than I should causing the fuel pump to kick on more.

Any ideas? Thank You