diamante running hot under load
 

hi all...i have a 2001 diamanate vrx...3.5v6..5speed tiptronic auto..227000km....last few months have noticed temp rising when going up hills or under load,towing etc...drops down once crusing again...if sitting in traffic its fine temp needle sits middle of temp guage or slighty under..both fans working...was going to change coolant(hasnt been done for a while)and thermostat to start or is it just better to bite the bullet and let the experts have a look...cheers