From great to opps in one easy step!

New radiator fitted, also replaced thermostat (74 degree) and otter switch (88 degree) to lower temp ones (just because whilst I'm sorting the cooling system out - why not).

Fired it up and bled the system.
Took it out for a drive and heard something 'ping' off - followed by a worrying rumbling noise.
Was only up the road from home so pulled up on the drive and had a look - OH DEAR.... looks like I didn't tighten up the alternator pulley bolt enough - luckly it's just stripped the thread on the alternator and ruined the pulley.

Got a new pulley and have put the alternator in for a repair.