As I look back I had two near misses this summer, both on hot days, after 15-20 minutes of slow traffic ie just the fan running at barely above idle, and no air ram effect on the rad... I pulled over quickly each time, let the engine cool, and then as soon as the traffic cleared, hit the open road and no problem, back in the centre of the dial. OK, so I did subsequently have one HG go, which I'm sure wasn't helped by the first over-heating episode, but a HG change was in the tea leaves anyway.
So my question is, should I expect (and so try to avoid) these kind of heavy traffic/ hot weather over-heating scenarios, or does it sound like my waterways might be bunged up (ooerr). All the hoses are changed out since I bought it, but I haven't touched the water pump (yet) or the rad. The system did have some rad weld in it for a few weeks last year, but I have done a couple of changes of the coolant since then. I was wondering if the radiator was free flowing...if I stuck a hose in the top of the rad and blasted it through would it make any difference, or should I consider a new rad - I couldn't swear to it being the original one, but it's certainly the normal abs/ aluminium build and so possibly due a new one anyway