Posted 19 June 2009 - 09:37 PM
To get back on topic, why would leaving the rad cap off cause the fan to hit the rad? Did the cap fall down between the rad and the engine? We used to have a joke on a friend who did just that: Maintenance tip of the week: the easiest way to disantle the rad cap is to drop it into the fan!
It does no harm whatsoever to run without the rad cap on (so long as it doesn't drop into the fan area, obviously) so long as you keep the water topped up. With the cap off, the cooling system becomes what used to be called an 'evaporative loss system' as opposed to a 'pressurised water system'.
In fact, if you have any small leaks from the water system, it can be a great help to remove the cap so that there is no pressure in the system to force the water out faster. The water loss from a small leak is then minimised and so long as you top it up every few miles you can often complete a journey. It's then easier to top up, as the system will not scald you when you remove the cap. True, it can throw a bit of dirty water over the engine bay at that end, but that's easy to wash off.