09 G37 coupe A/T. Starter spins, does not engage
flywheel. Checked all fuses, fuseable links and relays. New battery and starter. Old starter still works. No corrosion found. Just started doing this. 11.67 volts on wire to starter when push to start activated. Any ideas? Both start relays have to engage to provide voltage to starter wire. Got that but starter spins. The solenoid does not activate. The flywheel and old starter gears are perfect. Im about out of ideas short of putting my own circuit in. . Thanks in advance

 

Are you 100% confident the "new" starter isn't defective? Quite possible the solenoid on the new unit could be defective. If the starter motor is spinning but the bendix is not extending/ engaging the teeth on the flex plate (flywheel) then 99% of the time the solenoid is the issue.

As you indicated the "old" starter "still works" indicates it is a mechanical issue with the replacement and not any of the wiring/ circuits/ electrics.

If the old starter is still good what was the reason to replace?

 

My son already ordered it. Installed new cam shaft sensor then this issue. Tried Jumping it. Same. Starter spins.

 

Could be a bad solenoid, plunger, pivot bearing, bendix sleeve...any of a number of small parts preventing the bendix from extending.

If the old starter is good, return the new one, as defective, for a refund.

No sense in stressing over a problem that doesn't really exist.

 

2 starters with identical problems? Even checked and the bendix does (with jumper cable) work just not on car? Thank you anyway.

 

That is not what you stated earlier:
So I am not sure where 2 starters come in.

I would CAREFULLY, run a jumper wire directly from the battery to the "S" terminal on the starter. If the engine turns over then the issue is the "S" line. If it still spins freely it's the starter.

Still doesn't make sense. With voltage applied to the "S" terminal, the solenoid pulls the plunger which extends the bendix. This action simultaneously closes the circuit between the "B" terminal and the starter motor. If the starter motor is spinning then that circuit is closed, but if the bendix still hasn't extended then normally it is the solenoid or bendix drive failing. But as you have "two starters with identical problems-" it "could" be a voltage issue.

Perhaps others will chime in as it appears I am not fully understanding your symptoms. Good luck

 

Even though the S line has voltage (11.67 volts) maybe it's not staying or strong enough to kick the bendix. I'll run a jumper cable to and see what happens.

 

I just got mine out if the shop.
After replacing the starter and a few sensors they came to the conclusion it was the key fob. Now it works fine.

 

I thought because of the P340 code that the Phaser had slipped. I planned on looking at the two but it snowed 6 plus inches here. (south Alabama) . I will try the FOB thing. Sounds much better than tearing off the front of the engine. Thank you!!

 

update. I tried the other key fob. No luck. I have to look up the timing marks to get it at TDC so i can check the phasers. I pulled the can sensor out and tried it but it nudges just a bit. Am i supposed to see the same thing in each cam sensor holes? The only code is the p340 p345. Ill update after i find TDC and check the phasers. Thanks for the replies.

 

Have to back up a little. I now have a new battery that isint junk. ( plus a new battery amperage tester). I put in the new Hitachi cam sensor. I've been saying the starter turns over, well it does but I don't know if the engine turns. I checked the pin inputs for the cam sensors. I believe it should be 12vGND5v. I have 5vGND5v. So I think the ecu is bad.. Gotta read more on this. Anybody verify this? I watch a video on how to remove. (Still looking for that comfortable spot 🤣.

 

Well, the starter is working perfect. However, I can move the flywheel with 1 finger. Goes around so nice and smooth. 🙄. Now, on to frop the Trans to figure this out. Crazy days.

 

Wait, the flywheel freespins but does the front assembly rotate at all? If the flywheel "freespins" then it sounds like something catastrophic has happened. Could be either the flywheel bolts sheared or, worse, broken crankshaft.

Until you drop the transmission you won't know for certain.

Either way, doesn't sound good.

 

The strange part is I xan move the flywheel smoothly. No grinding just nice smooth flow. Kinda scary. Still, rather replace the trans than the engine.

 

If the flywheel is turning and the crank isn't (as evidenced by the crank pulley/ belt not turning) then the flywheel has become "separated" from the crank. If the flywheel, or flex plate as they call it these days, is able to move with a fingers touch, that's not a good sign.

I doubt the transmission is the issue.

Please keep us updated and good luck.