Many thanks for the prompt reply & diag.
I am going to modify it so that if the fan is running at the time of engin switch off the fan will continue to run for a few minutes.
Despite all the cooling system checks out OK & holds pressure OK when hot, mine runs vey close to overheating when switched off on a hot day.
PS the left hand side of the image sent is clipped, I have all the info I need but if theres anything worthwhile on the LHS and its not a hastle I would appreciate it.
I am heading off on hols so wont be logged on again for a couple of weeks.
Well the problem turned out to be the system was pressurising OK but on really hot days when the engine was turned off the cooling system did not stay presurised long enough resulting in the coolant occasionally boiling.
The radiator neck appears ok but I think it has warped slightly (like me).
Interestingly the lower plastic radiator tank outlet is very oval in shape co it looks like the plastic tanks can distort.
Any how no further problems since I replaced the radiator.
Thought you might be interested.