even after vigorous driving my cluster only indicates an engine temp of about 150 F. i checked the block with an infrared thermometer, and sure enough, 68 C. on this basis i think the sensor and gauge are working. getting up to temperature i have no questions about, i have just read so many posts about temperatures north of 90 C that this low reading confuses me.

my (W126) radiator fan appears to run nonstop. would a failed viscous clutch have this effect on temperature, or is something else likely to be afoot? do i actually have a problem?

thanks for any tips.

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'77 240D, 504H, OM617.952, etc.