Quit throwing parts at it...unless you know they are old and you can afford it.

You need to check to see if you Main fan it engaging. I forget the exact temperature but it is before 100. 100 is the next line above 80. At 105 the electric fans in front of radiator should turn on, please test that and let us know. I have dealt with this on my 1987 300TD, I can probably help!

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1987 300TDT - 195,000 (Original #14 head)
1993 190E 2.3 - 105,000
1981 300D - 250,000