Keeps Killing Starter Motors

As I wait in the “warmth” of the landy for the AA to arrive for second time in 3 months for a seized starter motor it’s a good time to pick peoples brains on what’s going on!!

It’s a 2.5n/a diesel that’s been transplanted into a series 3

Looking at the service “history” it’s had 3 starter motors since 2021. And then in my ownership in November it had another when that seized. Now I’m sitting here in 0°C weather and it’s seized again. The first one that seized on me I thought that I might’ve been cranking too long. But this time, the engine was already warm after being driven 20 miles, I go to start it and I get three turns of the engine out of it before it once again refuses to turn over. I check it and it was hot to touch, but I don’t know if that’s residual heat from the engine or if it’s from those three puny cranks.

So what’s killing them?!!

Options.
Poor electrics, as in the cables aren't up to it.
Heat soak from the exhaust.
Or the wrong starter for the ring gear.

What sort of starter fitted? Inertia or pre engaged.

tottot said:

What sort of starter fitted? Inertia or pre engaged.

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Not sure on this one, how would I tell?

Ok so turns out on this occasion it wasn’t the starter motor!! Since it had the same symptoms as last time I was sure it was but when recovery got here they tried a jump pack and it started fine! What an idiot! (I blame the cold)

Now to test whether it’s the alternator or the battery, but recall I think the belt is slipping too much. Multimeter and jump pack on order!

For info. A inertia starter is just a plain motor case, the spinning of starter motor sends the gear to engage with ring gear on flywheel.
A pre engaged unit has a solenoid on the outside that puts cog in gear with ring gear before motor spins.
It is usual that only petrol engines have the inertia type.
As yours is a engine transplant I was thinking as @Wildefalcon is it the right starter.

Ah got it, definitely has the solenoid on top of the unit.

I wouldn’t be surprised if it’s poor electrics, there’s wires zigzagging all over the engine bay, many not connected to things. (High beam flash doesn’t work but I think that’s the stalk switch as everything else does)

It all works, but it’s how well it works that’s the real question