Hello Board,
My 300E has been running high temps(110 C at idle with A/C on) for a while. I thought my coolant needed to be flushed. Well I flushed the coolant, added a radiator flush additive(Prestone Heavy Duty) and despite all that my car still runs hot. My aux fan kicks in at 100C, but the temp still hits 110 C, but it does not hit the 120 C mark(thank goodness!!) I am afraid that the constant pressure and heat (110C) will hurt my head gasket. I have done this so far:
New Thermostat 1 week old(87 deg)
6 month old aux fan
2 year old radiator
50/50 mixture of coolant and water
still no improvement
Is the position of the little hole in thermostat critical for proper operation??
Should I have my system professionally flushed??
Help!!!