In trying to disconnect the 24yr old oil cooler lines from my oil cooler,
I wasn't surprised I butchered them. OK, before I replace the oil cooler
iw/a used unit--hopefully find one w/good threads--or invest stupid-$
in an OE or OEM one, has anyone upgraded the OM603 oil cooler to a
larger capacity custom one?

Seems it'd be about the same price as a Benz OE one. Also seems to
be enough room in the L/F wheel-well, to mount a larger size cooler? I
have a shop ready to make-up a set of SS braided steel lines. Replacing
the decayed 24yr old lines was the whole reason for this exercise, in the
first place.

Is a 140-series OM603 front-mounted oil cooler capacity? It looks bigger.
Is it larger than the 124 one I have... will fit under the 124 bumper?

-Will
'87 300TD
196K mi.

Although it's certainly possible to jam a slightly larger cooler into the space provided, I don't think it's necessary unless you regularly put an extremely high load on the vehicle in difficult terrain and environmental conditions and maybe not even then. For example, I find that I have difficulty getting the temperature of the oil in the pan of my '87 300D to rise above 200F (95C) in normal driving.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Thanks Jeremy, good hard data! How do you measure oil temps, btw?
A sensor? I can hear my engine 'rattle' more, as hot oil thins out--esp
idling in NYC traffic. Though not a heavy load, ALL cooling components
(Radiator, Viscous Clutch/ Fan, A/C Fans, Sensors, etc) must all be at
100% to keep this OM603 from overheating. Since I've got to get a new
oil cooler, I figured why not upgrade f/max oil cooling, too. It does look
like they gave the W140 OM603 engines a larger, front-mounted
Oil cooler. Benz must've had a reason--124 my wagon weighs about the
same as the 140.

I have a (permanent) VDO oil temperature gauge in a panel (replaced the ash tray) with a sensor where the oil pan drain bolt used to live.

I also have a (temporary) electronic thermometer with a thermocouple stuck between the fins of the oil cooler close to the intake end of the oil cooler. It's surprising how long it takes the oil to come up to temperature, much longer than the coolant. The oil cooler gets hot oil from the oil filter housing via a thermostat that (according to FSM) starts to open at 90C and is fully open by 110C. The oil pump pickup is situated not far from the drain plug so the oil that gets pumped to the oil cooler should be similar in temperature to the oil coming into the oil cooler.

However, my thermostat seems to open early: once the oil pan temperature is above 50C the oil cooler starts to receive oil from the engine and the temperature gradually creeps up from ambient (whatever it is outside at that time). When it's colder outside, it takes longer for the oil cooler to warm up, of course. I have no idea what happens in places where they have real winter (that white stuff on the ground). The two temperatures more or less track each other until both are around 90-100C. I haven't had the opportunity yet to drive the car hard in hot weather.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

With the 617.952 Oil Coolers it is possible to replace the stripped Nipple with the same type of Nipple that the Oil Cooler Hoses thread onto at the base of the Oil Cooler.
There is 2 good threads on that.
DIY Repair Links
http://www.peachparts.com/shopforum/diy-links-parts-category/

http://www.peachparts.com/Wikka/DoItYourSelf

However, I do not know if your year and model uses the same sized threads on the Oil Cooler Hoses.
For the 617.952s the Oil Cooler Nipple threads are M22x1.5.

If a Thermostat in the Oil Filter Controls the Oil going to the Oil Filter it will not matter too much how big the Oil Cooler is; with the exception that a larger Oil Cooler will Cool the Oil Faster.
As the other member said it would take some unusual load to make a larger Oil Cooler useful.

__________________
84 300D, 82 Volvo 244Gl Diesel