Quick Question for my lad for his Mk4 golf.

When he starts the car the starter motor seems to stay engaged for a fraction until the engine throws it off.

Is the return mechanism mechanical or electical?

I'm thinking mechnical could be resolved by removal, a clean and a good dose of WD40 but electrical may need a new stater motor.

He says he can't afford a new motor but sooner or later its going to knacker it or the flywheel which would alot more expensive.

Try pulling off the small lead from the solonoid when the starter is still engaged , If the problem stops it could be a faulty electrical section of the ignition switch. Worth taking the starter off and cleaning the pinion then a squirt of WD40.

Sounds like it could be a sticking solenoid on the starter motor.

This is a common problem on MK4 Golfs, IIRC it due to grease/corrosion on the motor shaft.

obviously don't use petrol or thinners to clean it