just a heads up on this drive cog on these pumps are prone to failure ,believe me i know on investigating mine it had partly collapsed but kept driving albeit dropping the oil pressure. The cog can be bought separate from the pump think from memory £30/£40 ......
The Mechanical Engineering lecturer at my college used to shout at me for saying 'cogs'. "It's GEARS boy, GEARS!! Cogs are for clocks" 
I'm sure there was a recall or something on early GTIs to fit a stronger nut/bolt for that 'gear'? I remember when the GTI first came out there were reports of sheared off oil pump drives. Pretty sure it's a rare occurrence on 2007-2009 GTIs.
You've shown your age here Puddy
The MK1 GTI was a gem in my opinion sounded awesome with the right backbox exhaust!
Just out of curiosity.. what were the so called, if any, improvements and adjustments made to the earlier MK5 models in comparison to the latter i.e. 2007-2009?
I know from own experience driving several MK3 models that the earlier VR6 engines were different to the later VR6 models. But they all shared one thing i.e. overheating! I’ll never forget when my mechanic had to strip down the whole dash in order to get to the heater matrix inside! Stupes design! What amazed me was how my mechanic was familiar we reassembling all the wires and looms and nuts/screws back in place! It as a pretty huge job! Costly too.
