Gen3 (G13b) flywheel teeth/gears gone?! Horrible griding sound (video).

Hi again,

So - replaced old starter which was intermittently not working, with a brand new one last month. Car seemed to be great.

Last week, drove it to tesco (short drive). Didn't start again, with a quiet but definite grinding noise. Was late at night so rang the missus who came down to try and bump start it with me. We didn't manage, but afterwards it started with the key, completely fine for over a week - worrying, but somewhat ignored due to needing the car.

Took the dog to his favourite woods this morning, started no issues and drove fine. Went to leave and it wouldn't start again with a faint grinding sound - I half expected this might happen so had parked on a slope. Pushed the car slowly, jumped in and chucked it into first as not fast enough to bump start. It sort of spluttered and stopped... but then started with the key afterwards.

Anyway - its home now and absolutely will not start and produces this horrible grinding noise in the vid below.

I have a suspicion that maybe the original starter I replaced wasn't the issue and the flywheel gears were going/are now gone? Or perhaps the engine is seizing because its cold - but this seems unlikely? I'm hoping someone has seen this before and its neither and you'll point me to a wiring issue, but I suspect more devastating.

Very recently had a coolant leak from the stat housing - just replaced that and its now solid, but potentially coolant spillage has ruined something?

The car is a project and I was hoping to do a clutch/gearbox service at some point - so if it is likely a ruined flywheel it could be bundled into this task!

youtube.com/shorts/tl8ktKtLokg?si=pOxH6lxIKT32Oi8t  
 

Is the engine turning over or not? I can't see any pulleys in the video.

Assuming not then what can happen is the flywheel teeth wear down.
The engine stops in only 2 places, so the teeth in those places take a hammering. If one set have gone, then it will start if the engine stopped 180 degrees out.

Turning the engine forwards a few degrees by hand should move fresh teeth to the starter and it might start as it will be moving when the bad teeth get back to the starter.

Why might the teeth wear?

I had a Jeep once (an AMC one with the 4.2 straight 6) that took the tips off the starter motor teeth because the starter was not fully meshed with the ring gear- someone had fitted a starter with a different sized locating ring to the hole in the backplate and it could move outwards on the bolts.

If the engine has been a very poor starter taking several attempts each time this accelerates wear.

If it is the wrong starter and the teeth don't mesh properly.

If it is the teeth on the flywheel/starter motor then it will need a new ring gear on the flywheel (or a new flywheel, it may not have a separate ring gear) and a new starter gear/starter motor to match.
 

Thanks for so much the quick reply.

No the engine isn't turning at all, I'll try and turn it by hand and see if it meshes - this certainly fits with it starting after attempted bump starts.

Try about 20 degrees at the crank pulley, in the direction it rotates when running, it should be clockwise looking at the crank pulley, I've never actually checked!

You absolute genius thank you.

It's definitely that and it started instantly sounding much smoother than it has for a long time. So I suspect the two locations where the engine stops the gear teeth are absolutely shot.