I have a '93 400E which is essentially the same vehicle. My temps sound about the same as yours. With ambient temps now in the 60's, it runs about 82 at cruising speed, but then like you I hit a stretch of bumper-to-bumper traffic and it will then get up to about 100 (and definitely would hit 110 in the summer months). Seems to take a while once back to cruise speed to come down, and never comes down to the low 80's once it gets hot.

I too have a new radiator and thermostat, and a relatively new water pump, so I THINK this is normal behavior of these V8s crammed into the W124 engine bay.

It will be interesting to hear from others. I have heard many different opinions on this subject. Some say that any temp below the red line is OK, though that's hard to accept. It is interesting, though, that the engineers set the aux fans to come on at 105 or 107 degrees coolant temp, so apparently they weren't too worried about 100 degree temps!

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Steve
'93 400E