Starter

Old cars had those funny cranking handles at the front to get them spinning. Your E30 doesn't. Why not? Because you have a Starter, that's why.

Overview

The Starter is an incredibly powerful electric motor, designed to spin your engine up to a speed that's fast enough for the explosions to take over and drive the engine continuously. If your engine goes below that speed, it will stall and you'll need your Starter to spin it back up again. It's that simple.

It does this by driving a very small cog, known as a Bendix against the toothed edge of your engine's flywheel. This cog is pushed out from the body of the starter when you turn the ignition key by a solenoid; as soon as you release the ignition key, the bendix disengages and the starter shuts off.

The starter unit on all E30s is self-contained and non-serviceable; you can't separate the starter motor from the solenoid or its internal switching 99Starter#Relay|relay]]. Fortunately, there are very few reported cases of faulty starters, and the most common cause of starter motors not working is the wiring.

Components

The starter motor assembly is a one-piece unit, and is not designed with disassembly and servicing in mind. But it's worth knowing what's going in inside the assembly, so here's a run-down.

Wiring

Your engine loom will have four wires.

An E30 facelift motor should have two 8mm studs, one 6mm stud and a 5mm one.