On Sat, 27 Jul 2013 15:14:29 -1000, Geoff Welsh
wrote:

Guv Bob wrote:
....The cooling system has been starting to overheat for the
past few months when it's a idling for more than a couple of minutes.
.....


I fail to understand why you are worried about colors and noises on a
vehicle that is constantly overheating.

Have you had a block test done?

GW
As I stated - if the pH of the coolant is too high the radiator will
scale and it will NOT cool properly. If the pH is too low (acidic) the
radiator will corrode and leak.

If it overheats at idle but not on the road the primary suspect is the
fan clutch. Next suspect is a restricted rad (which would usually also
heat under heavy load) - (either air restriction or restricted coolant
flow)