I'm trying to get to the bottom of some trouble I'm having with my car starting. As it says in the title, it's a 2001 Saturn SL1 which I've owned for about a year and a half. It's got about 107,000 miles. The problem has only been happening since Thanksgiving 2011, and I do live in Southeast Michigan, so it could be weather-related, I guess.
Sometimes, it won't start. When this happens, it makes no noise at all -- I don't hear it trying to turn over and failing. The lights on the dashboard all still come on, the radio works, etc. My mechanic has tested the battery and thinks it's fine. The car will always start the first time I use it in the day. If I do stop, for example to go into the grocery store, that's when I run into trouble. Sometimes it will start when I come back out, and sometimes it won't. If it fails to start, waiting about 45 minutes will let it start again. Also, a jump start will always start it. It's never failed to start after a short stop, like getting gas, and of course it's never failed after a really long stop, since it's always fine after 45 minutes. Some length of time in-between is the magic time.
I left it with my mechanic for a day, and they said they couldn't get it to fail to start. They think it's the starter motor, but don't want to put me to the expense of a new one if they're not sure. Is there anything else it could be, though? And how could I test it?