The cooling system does not seem to be working correctly and if it overheats only when at idle, it is either the radiator cooling efficiently is below par or the coolant movement are restricted.
Apart from those you have done, check for clogging in the pipes, especially iron pipes which might get reduced in size due to accumulation of rust etc.
Is the radiator fan shroud in good condition? Have you checked for air restriction due to clogged fins of the AC condenser?
Monday, November 14th, 2011 AT 12:18 PM