I have a 2019 Subaru Crosstrek. I was out of the country for 9 months so left it garaged. I just got back and tried starting it. It jump started immediately which was great. I let it idle for a few minutes and it seemed to be running ok. There was some white smoke out the back but I thought that was probably just stuff burning off. There was also a gross smell near the engine bay. I went to go drive it around the neighborhood and as I left my garage it just shut off. Now it won't jump start even (it's possible booster is just low on batteries). What are the likely root causes here?

Have I caused damage by starting it?

  • What happens when you try to jump start it, do you hear the starter motor turning the engine over?
    – HandyHowie
    Oct 13, 2023 at 14:02

1 Answer 1


It sounds to me as though the alternator isn't working correctly. It could be caused from a very low battery not giving it enough of a reference voltage to actually charge it. Starting it with the jumper gave the system enough power to get started and running. When it was running, the car quickly used up what energy was there and then died.

The charging system in vehicles isn't really made to completely recharge a dead battery. It is designed to keep things running and to replace the minor amount of power which was used during starting.

My suggestion is, recharge the battery fully with a portable charger. If the battery will not accept a full charge (12.5+ vdc), then it needs replaced. Once you get the battery recharged and the engine running again, check the voltage at the battery and ensure it is maintaining 13.1+ vdc and not dropping. If it is dropping, there's an issue with the alternator.

  • Like stated, battery and alternator would be the most likely cause because of 9 months of storage. But did you check the oil before starting?
    – Jupiter
    Oct 13, 2023 at 14:01
  • 1
    Run out of fuel? The gross smell from the engine may be a cooked nest or dead animal.
    – F Dryer
    Oct 13, 2023 at 15:55
  • And if the mice/rats chewed on cables that charge the battery from the alternator, you get bad smell and dead engine from one cause. (Rodents are well known to nest in engine compartments and gnaw on cables. At mountain trailheads it is not unusual to see vehicles left with their hood up to discourage rodents nesting while the owners are out backpacking of whatnot.
    – Jon Custer
    Oct 13, 2023 at 17:44
  • And to add to the comment about the alternator not being designed to fully charge a battery... I was told to always use a trickle charger for a dead battery, and not to simply jump start it and let it idle or drive to charge, because it is too much of a load on the alternator, which will get very hot, and possibly damaged. Dec 6, 2023 at 4:43

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