Just picked up a 1991 300D with 78,000 miles on it. Everything is great except the operating temp.

Symptoms: will settle at 60, maybe 70 on highway. Will occasionally reach just shy of 80 (e.g. after getting off highway). Origially assumed bad thermostat, but fan spins freely when engine shuts off whether hot or cold, so I'm assuming bad fan clutch.

I guess my main question is this: am I doing any signficant harm by letting it go for a couple of weeks at these temperatures (i.e. 60-70)? I just am not able to take it in right away.

Thanks.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 158k miles
06 E320 CDI "Rutherford", Black on Tan, 177k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 144k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 72k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife