Originally Posted by Hit Man X

Car's temp will not climb very high on the freeway due to airflow. Mine did not with the 87°C... but as soon as I slowed in the summer, the temp would jump to 100°C pretty quick. Mind you 100°C is not HOT/boiling over by any means, it simply hampers acceleration of the vehicle and heat soaks the A/C condenser more easily.

Due to your climate, run that lower temp thermostat I pointed out previously. The A/C switched on plus a locked fan clutch really makes the M103 work overly hard to propel the 126 around. When I said takes longer for the car to become hot, I mean from ~80-100°C... not the warmup phase. Mine warms up quickly even when we have cold snaps here in the winter.

I really have no idea why MB installed the 87°C in the M103 when everything else I own from them came with the 80°C area units of that area. I can only assume for emissions or something of that nature.

Plus, get out the trusty DVOM and see if you have power to the dead aux fan. If so, it may simply need brushes or a good cleaning to function again. Hell it could simply be unplugged.