I'm not 100% sure about this but I think there are some 94/95 E320's with an oil cooler. If you have this option, you should see two lines connecting the radiator and the oil filter housing. I believe the cooler is integrated into the oil filter housing.

Maybe this oil cooler was part of the hot weather option?

J. M. van Swaay

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1994 E320 Wagon, 230,000 miles
1995 E320 Sedan, 106,000 miles
1994 E500 Sedan, 79,000 miles