I have just recently replaced the water pump on my father's '93 E320 coupe (M104). The job was much easier than it looked (and I was lead to believe it would be). It appears it would be a more difficult job on our M103 (never had to do it yet). I also replaced the belt tensioner, tensioner damper and belt as a precautionary measure since I had them all removed.

When ordering the pump, I was asked whether or not the engine had an oil cooler. The oil cooler versions of the pump have an additional pipe at the rear which this car does not. At the time, I was informed that the pump I needed, a 104 200 2801 was no longer available and that I would have to use a 104 200 3301 and plug the extra port. The only problem was, no one could explain to me how this should be done. Eventually, a 104 200 2801 pump was located, so I did not have to deal with the problem.

This leaves the question as to just how does one deal with the extra port on the 104 200 3301 pump? Looking at one, a logical solution would be a cover plate retained by two screws into the tapped holes (provided in the pump). The plate would retain an O-ring in the groove around the hole to form a seal. I am told such a cover plate is not available so therefore is presumably not the solution.

Anyone know the answer to this one?

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107.023: 350SLC, 3-speed auto, icon gold, parchment MBtex (sold 2012 after 29 years ownership).
107.026: 500SLC, 4-speed auto, thistle green, green velour.
124.090: 300TE, 4-speed auto, arctic white, cream-beige MBtex.
201.028: 190E 2.3 Sportline, 5-speed manual, arctic white, blue leather.
201.028: 190E 2.3, 4-speed auto, blue-black, grey MBtex.
201.034: 190E 2.3-16, 5-speed manual, blue-black, black leather.