I just picked up an 83 240d 4 speed with 155k miles. I noticed the oil cooler was missing on first inspection and i drove it home 4 hours away. It ran great and no overheating as I watched the temp on the drive home . Is it ok to drive it without the oil cooler?

Well...??? Probably. If I were to do that it would be on synthetic oil with at least 1200 ppm of ZDDP e.g. Valvoline VR1. I wouldn't do it on dino oil unless I had an oil temperature gauge. Wouldn't consider it on a turbo car but you're safe in that aspect.

The coolant temperature gauge will significantly lag behind actual oil temps.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

Well...??? Probably. If I were to do that it would be on synthetic oil with at least 1200 ppm of ZDDP e.g. Valvoline VR1. I wouldn't do it on dino oil unless I had an oil temperature gauge. Wouldn't consider it on a turbo car but you're safe in that aspect.

The coolant temperature gauge will significantly lag behind actual oil temps.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

So in summary...driving it is ok you are saying? With fully synthetic oil only?

I think it would be ok but of course there is some risk and in other ways there is less risk e.g., no oil cooler or hoses to fail.

Where would you operate it, what ambient temp?.

Yes I'd only use synthetic oil that has sufficient ZDDP.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

IIRC 220D's with a similar engine didn't have oil coolers from the factory.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

I seem to remember reading that M-B installed oil coolers on cars that were originally equipped with AC.

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- Greg -
1973 220D, The Prodigal Benz
1974 240D

My '78 240D no AC had one but it was about half the height of the 300D Turbos. My '76 240D w/AC had the full size cooler.

Dad's 380SEL euro w/AC had a full size cooler. When I changed the radiator I eliminated it to be able to fit a US radiator.

I don't know MBZ's criteria for cooler or not???

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

I am in connecticut. So not that bad temp wise

If I read your initial post correctly, your 240d is a manual 4 speed.

If so, we've had 2 of those over the years, and neither had an oil cooler, nor had problems running on dino oil, in the mid Atlantic state heat. I don't think they were installed unless the trans was an automatic IIRC.

I believe my 72 220d had an oil cooler. I believe they built them without coolers for cars destined for cooler climates. I would not worry about it.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Hey, my 84 240d engine i have in my 123 hasnt got one either, the filterhousing is designed without it. In addition i have added a turbocharger so you will be fine.

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W124 230E 88 5 spd M103 3.0 swap

W123 230 auto 78 240D-turbo Swap daily

W115 200 75

Not sure we'll figure out which versions got factory coolers...my '78 240D manual transmission, no A/C, sunroof had a half/tall factory cooler without a cooler drain plug. Go figure.

May well have been decided by climate expectations and I won't go down that future "rabbit hole".

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer

My 84 grey market 240 has no oil cooler.

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1985 300 TD 448K
1984 300 TD 278K

1983 240D euro 240k
1994 f-250 idi turbo 330K
1986 f-350 IDI
1987 F-350 IDI

1985 JD 1050 4wd
1965 IH 3660

Shadetree, How did the factory cap, loop or eliminate the hoses at the filter housing?

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer