560SEC overheating
 

My dads 560SEC is overheating. We have replaced:

Fan clutch
Waterpump
Themostat
Coolant, 50/50 mix (3 times for each of these jobs)
The Radiator looks relatively new, but i could be wrong. But we have washed it well with the hose a few times.

After all these replacements the car still runs hot, without the AC on and under normal operating loads. The problem gets worse when stuck in traffic at and idle.

The Aux fan does come on at 105 degrees like it should, even so the guage still reads 105 degrees or more. Could this be the guage sensor, or is there something im missing?

~mark

Is it actually overheating....
I recently had a similar problem on my 500sel, the car was running normally at around 95'c, and in traffic up to 105-110. I waited a long while after a good hard drive for the aux fan to kick in, and the gauge read 110-115 and was fluctuating. I replaced the temp sender for the gauge... and no more 'overheating'!