I have a 2007 Subaru Legacy 2.5i (naturally aspirated non-turbo) where everything lights up on the dashboard when turning the key as it should, but every once in a while, moving the key that last little twist from the On position to Start does nothing. Everything looks, sounds, and feels correct except there’s no cranking. Usually, trying again immediately will cause it to start right up. But sometimes it’ll just sit there and not crank, no matter what I do.
The battery was replaced to no effect; it’ll start, but do this no-crank thing once every handful of starts. Changing the battery-to-starter cable did nothing. I left the car with my usual mechanic for a full week, and it started every time for them; the starter drew power as it should, the alternator was working fine, the cable connections were fine, and there were no fault codes stored.
I got the car back from the mechanic Friday and it was running fine for a full day of running errands Saturday before the same thing happened again that evening. I popped the hood and tried jiggling (flexing) the positive battery cable. No change. Then I tried something different; I tried listening carefully when twisting the key: the dash lights came on and I could hear a buzzing that was probably the fuel pump. I waited until the buzzing stopped, then twisted the key to Start. The car started right up.
This car is equipped with the factory alarm and comes with chipped keys. I’m not sure it’s the immobilizer since those stop the injectors, not the starter motor, right?
Any ideas what’s going on here?