Occasionally when I start up my 1.9SDI, just after letting go of the key I get a weird noise that's a bit like a gear grinding, for a couple of seconds and then everything goes to normal. I've got no dash warning lights showing. It doesn't happen every time and I can't figure out what or why it does it. I'll try get a video tomorrow but just wondering if anyone else has had this issue? Should I be worried? Car drives fine. 

Sounds like the starter motor solenoid sticking on perhaps? Could try removing the starter and cleaning everything up to see if it cures the issue, it's not too hard to get at but the battery, battery tray and possibly air box need to come out to get access. 

mine does the same thing! can you get it from underneath?

I second starter motor.

Depends what engine but most are all easy access at the front of the gearbox.

You can access it from the top but you need to remove the battery, battery tray and possibly air box. I'd personally rather attack it from the top than crawling about on the underside but you can access it from there by the looks of it. Not sure how much room you'd have to swing tools about mind. 

anyone got a guide on this? I did try a search but im going blind i swear...

What engine you got?

umm, 2002 1.9 SDI (aka the slug) can probably find a code if you need it, but its dark right now