1987 300E coolant temperature / fan clutch

[murphysf]

Hello

I have a 1987 300E since 2001.

I have noticed when the vehicle sits in stop and go traffic or if I leave the car running when I get home for 10 minutes or so the temperature slowly creeps up and eventually the electric fan comes on at 105C, and it seems to stay on, or go off briefly and come back on.

The radiator and thermostat are in good shape.

I am thinking the fan clutch might be a bit worn.

The fan clutch does engage and spin however I was told that it didn't seem to spin that fast. I was told they tend to roar a bit. My fan clutch plastic fan version has 11? blades. I see that the replacement is 9 blades.

Its behavior has been the same since I have owned it (18 years).

I recall reading threads over the years that other owners mentioned that the temp creeps up in stop and go traffic.

There is a youtube video that shows the safe way to test it.

When the car is cold by had the fan will spin for 1 to 1-1/2 revolutions. When hot and the engine turned off the fan continues to spin for a while. The video mentions it should come to a stop much sooner.

Any ideas how to be certain my fan clutch isn't working at its peak.

I'd rather not have it changed out unless I am certain it is bad.

???

Thanks