Hi, am replacing my oil lines as the lower line is leaking and ready to go soon. I drained engine oil and later loosened lower oil hose fitting from oil cooler and let it drain . . . . I had over a quart of oil drain out. It seems to me that draining the oil cooler each time for an oil change is a good idea given how much oil was actually in the cooler and lower line. This quantity of dirty oil would foul new oil pretty quickly. Fortunately, the threads on my oil cooler fittings were in great shape allowing me to remove lines with little effort. Monday I will take my lines in to a local shop and have new line crimped onto fittings this ending my leaky lower hose saga and creating peace of mind for future road trips. My SD has over 290,000 miles, looks beautiful and still running strong!

I wouldn't recommend that... I have seen earlier MBZ' with drain plugs on the oil coolers. It was on a 1968 280SL.

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My Truck.. 2007 DODGE, 5.9 Cummins, 6spd stick, 4X4. My car..1977 240D, OTHER WHEELS...1955 VW Oval window bug, European Delivery (Holland) with a 1700cc, 2 barrel, Porsche drum brakes. 1939 WILLYS Pick-up. 1967 Triumph 200cc Tiger Cub. 1976 Honda 550F 4cyl Motor Cycle.

wouldnt recommend what?

I think he means not removing the oil cooler lines to get that oil out when you do an oil change. Oh, darn it! today is oil change day for my '85 300TD!
I have seen the threads on the cooler come out on the hose fittings. Unless you are starting with a new hose or put some Alunox in the threads I use that stuff religiously on threads, I have even been known to put it on flashlight and caps:
new ends on oil cooler lines OM603 '87 300D turbo Ouch!!!!

Still wish I had my 115 300D with its drain plug on the oil cooler, I wonder why they stopped using that?

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

oh, as I mentioned, my threads are in great shape, lines cam off easily, as I mentioned, I think with the quantity of oil that left my OC and lines, it's worth draining . . might do a mod, or as Brian suggested previously, just loosen lower hose mount and allow to drip drain over night.

I bet the Deutsch engineers said "Vell, zie drain plug ist unnecessary, zie motor vill last just as long mit no drain plug. Remove it."

247k and 276k on ours so far, with no drain plug. I'm guessing it won't make a bit of difference.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)