[Dynomite]

Originally Posted by Blownrunner

It seems that everyone accept that the oil in the oil cooler does not get changed during a routine oil change. Did you know, according to the FSM, that the oil cooler holds 2 quarts of oil, about 20% of the oil in the engine?

Determined, I figured out how GM solved this problem: The oil cooler has a drain plug that is easily accessible on the passenger side of the car, aft of the center front spoiler, in the center of what appears to be a large grommet with an allen screw in the middle! Mine was covered up by some type of sealant or adhesive, which is easily removed. The grommet is actually the lower right mount that sandwiches the oil cooler/air conditioning condenser assembly in the front cooler assembly housing.

I am sharing this because it seems to be accepted practice that you don't drain the oil cooler at oil change time. I would be astonished if I were the first to discover this, or at least to post it on this forum.

Great Info........

Originally Posted by WVZR-1

I believe the "conventional wisdom" needs to prevail here because the plug the OP mentions isn't meant to be a "service port". I don't know the thread size involved here but for any thing other than maybe it's use to drain the oil for a cooler change seems maybe foolish. Any conventional engine oil drain plug uses a gasket or seal to prevent seepage and I'm quite sure this could only be some sort of an NPT plug and that's not a conventional method used for engine oil service ports.

Excellent Conventional Wisdom
I would expect that the flow through the Oil Cooler is of such significant velocity/pressure that contamination deposits would not STALL in the bottom of the Oil Cooler. Such accumulation of contamination deposits could over time close off the oil cooler. My thinking is that such deposits would be cleared by force (oil pressure and hydrodynamic cleaning) within the oil cooler narrow passageways. I am also thinking the Oil Cooler Flow is Filtered just after the Oil FIlter (just thinking).

Originally Posted by A26B

If I recall correctly, the oil cooler is not in the full flow path until the oil temp thermostat in the oil filter adapter opens. Prior to opening, the oil flow to/through the oil cooler is minimal, so that when the oil t-stat does open, the cooler is fully charged.
That is why you will not see any abnormal pressure lag after an oil change with an empty oil cooler, as mentioned by the OP.

I am assuming that this oil goes to the Oil Cooler after the oil temperature has opened the oil temp thermostat directly from the Oil Filter. I would assume that this oil is newly filtered oil having passed through the Oil Filter Adapter Housing.

Originally Posted by WVZR-1

Cooler by application part #'s is '90 - '93 and '94 & '95 a different part #.
'90 - '93 = 14104653
'94 & '95 = 10219643

I LIKE Part Numbers

Originally Posted by Jagdpanzer

I had my oil cooler out when I swapped in my new motor and it did not have any kind of plug like the OP mentions.

Great Additional Information
Meaning that Oil Cooler Part # 10219643 (94' and 95') does not have the Drain Plug.
This Oil Cooler information is for a your 1994 I am assuming