sunchaser500

Please help, operating temp 110 under normal driving conditions, A/C on, all fans working. Replaced radiator and thermostat, no change, I can turn on Full Heat and it will drop temp 5-7 degrees, seems like water pump is working fine, any suggestions????
Thanks, Ron

nenad16

fan clutch?

sunchaser500

fan clutch is o.k.

waybomb

Are you certain the gauge is accurate?

Even with the radiator fans running, you go to 110c? And it stays there?

What antifreeze are you using, and have you checked concentration?

hcetzneb

What did the old coolant look like rusty?? Could be lots of things.. Check with infa-red meter to se if you have any blocks, heater core could be block..

Make sure water pump is working fine ( moving water)

Check fan clutch... when hot there should be very minimal slipage..

It has a duo valve ( heater core shut off) this can stick.

In the end it can have a bad gauge.. make sure with a infrared therometer the coolant is at that temp.

sunchaser500

Runs at 110 C, which is 230 degrees even with all fans working. Coolant is about 90% concentration and is super clean, no rust.

I have someone checking the temp senser and guages for me now, i hope it's that simple. My Merc. Mech looked at it this morning and he couldnt believe the temp was 110 and the car had not overflowed thru the radiator cap yet, he also mentioned the top radiator hose did not feel as hot or pressurized as it prob should if that temp is correct. His main concern was cracking the head if the temp goes any higher.

waybomb

You do realize that antifreeze has less heat conductivity than water? For warm weather, go 50/50.

But I doubt that is your problem.

nenad16

first of all, the antifreeze to water ratio should be 1:1 or 50/50. second, if the temp gauge shows 110C and the overflow line is dry, you are looking at either bad cap, or lots of air trapped in the system. also, comparing the temp gauge reading with the CTS reading will tell you if the temp gauge sensor is faulty. the two readings should be about 5C difference, with the CPS reading being the higher value. also, the water pump can be the culprit too, it is not uncommon for the impeller to become loose or detach from the shaft, thus not providing the necessary water flow through the cooling system.

sosh

Most likely its the anti freeze percentage. Too high will cause it to run warm or even overheat. No more than 50/50 is suggested. Other scenarios are possible but unlikely.