The car has 150k miles on it and it really gets warm when stopping at a signal light. It seems once it get to a certain temp, 105 or above, it has a much harder time cooling down. The Aux fans work both the Air cond and coolant temp. My buddy suggested we change the fan clutch which we did, but the temp issue is getting worse. So our next step is going to be replacing the Radiator, everything else seems fine as far as the operation of the motor etc. My buddy is a Mercedes Mech. and seems to think it must be the radiator but also suggested I post here to see what the basic opinion would be.

Thank you for all the help and any more info would be much apprecaited.