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My wife owns a 2008 Nissan Micra/March, commonly known as the K12 (originally from Japan if that makes a difference). We've noticed over the last few weeks that, when starting the car, the starter motor doesn't want to "let go" of the engine. It's as if the person turning it over is holding the key turned longer than they should. It only "hangs on" for a second or two, but it's enough to be noticeable.

I haven't investigated anything yet, but I understand how starter motors work from a high level, and am I'm leaning toward this being an issue with the gears in the start motor. If you let go of the key before the engine catches, the motor stops right away, so I don't think this has anything to do with the motor receiving power longer than it should. Otherwise, the car starts up easily without problem, and runs well.

I've been lucky enough to find a workshop manual, and it shows two different diagrams for two different starters. I'd like to get an idea of what specifically the issue could be, and what would be required to fix it.

Can this be as simple as cleaning and lubricating some of the gears?

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    Could be as simple as the return spring no longer pushing the key back from 'start'. Make sure the key is actually returning first.
    – Zshoulders
    Mar 14, 2017 at 15:05

1 Answer 1

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I could be that simple. A binding solenoid/mechanism can cause what you are experiencing.

Looking at the top image, the solenoid (#7) is on top of the starter. When power is added, the solenoid moves the (#3) arm which slides the gear (#10) out to engage flywheel. When power is removed, the solenoid and gear should snap back. Lack of lube can cause this to bind or move slowly.

All the lube points marked with an H are important. As you can see, many of the points are where that gear slides and associated items related to it.

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  • I would think the solenoid retracts to move the gear into mesh with the flywheel given where the pivot point is.
    – Solar Mike
    Mar 14, 2017 at 15:14
  • I see. So the solenoid is responsible solely for engaging and disengaging the gears. I seems then like it might be a bad solenoid that isn't releasing fast enough?
    – raydowe
    Mar 14, 2017 at 15:23
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    It is possible.
    – CharlieRB
    Mar 14, 2017 at 15:35
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    The solenoid could be retracting however if the gear is sticking then even after the solenoid retracts the gear will remain meshed. The solenoid rod just pushes on the lever which extends the gear. Possibly the return spring could be broken. Mar 14, 2017 at 15:44
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    @RowanHawkins : the solenoid pulls on the lever - pivot point in the middle and look at item 12 in the top diagram - that is the gear that drives the one way clutch unit 7. The solenoid return spring is not shown but is inside the solenoid unit, and yes that could be broken, but the most common cause is dry grease or clutch dust causing stickiness on the shaft / gear item 12.
    – Solar Mike
    Mar 14, 2017 at 15:52

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