4.6is starting problems......

[M3 SOY]

Having searched the forum, and I may guilty of missing something, so apologies in advance if I have, but nearly every time I start the car it fires up as normal, but as the engine fires, I get a brief almost grinding type noise, similar to the sound you would get if you tried to turn the engine over when it's already running.

This problem orignally occurred when cold starting, but now does this nearly every start, even if the engine is warm.

I'm guessing it could be the starter motor, but not sure, and it certainly doesn't appear to be a common problem. That said, if it is the starter motor, is this a straightforward DIY or is it time to get raped by the stealer??

Any advice would be much appreciated.

Thanks