a close up view of the lousy design. Perhaps "lousy" is inappropriate. okay. I'll just call it like I see it: a piece of crap. a substandard attempt at weight and cost savings.

UPDATE:

Well. I have changed my mind a bit. The late style oil cooler...oil to coolant...is not really a piece of crap. Nor is it cheap: the price is about $300 from Volvo.

There are two things about it that I do not care for:

...it limits the amount of cooling that the motor oil can receive. The motor oil can not be cooled to less than the motor's coolant temperature. [IF to even that temperature]

...because it transfers heat from the motor oil to the coolant, it adds heat load to the motor's cooling system. During the model years that had these coolers, the radiators were larger than the older radiators...in part to handle that extra heat load; and in part because of the switch over to the use of electric cooling fans as the primary cooling fan instead of the clutch-type [thermally controlled viscous coupling] mechanical fan. The larger capacity radiators were necessary when changing over to a reactive cooling system.

If one were to increase the cooling capacity of the older sized radiator equipped motors, then the added heat load to the cooling system from using the oil-to-coolant oil cooler would likely be accommodated.

I prefer the separate oil cooler...oil-to-air...used prior to 1992. The oil can be cooled to temps lower than the coolant temp.

With that said, there is one advantage to the late style oil-to-coolant cooler: it does warm up the motor oil faster. As the motor is warming up, the oil cooler transfers heat from the warmer coolant to the colder motor oil. And in cold climates, that is a good thing.

Because of that one advantage, I will be exploring the use of both type coolers...working in tandem...for a particular application in the future.