: oil cooler

Harry Yarnell
09-13-08, 09:20 AM
I bought a '96 SLS with a grenaded motor (story to follow shortly). I have a good '96 motor out of a STS; the STS motor has engine oil cooler lines, the SLS doesn't. Can you just plug the ports, or will this starve some bearing within. In other words, do I bypass the oil cooler, or cap the ports?

09-13-08, 12:05 PM
You could probably get away with swapping the oil filter adapter from the old engine. Otherwise, the oil cooler circuit is set up with bypasses and controls for the STS radiator.

Don't forget that the STS engine demands a different set of electronic controls, PCM, and final drive ratio from the SLS.

Harry Yarnell
09-13-08, 03:23 PM
I guess if I'd a looked, I coulda seen I could just swap the oil filter assy. Thanks Sub...
As for the difference between a SLS and a STS engine parameters, what is it? Cam profiles? Compression ratio?

09-13-08, 04:49 PM
The SLS uses different cams from an SLS, so the torque, ignition timing, and fuel curves are different in the PCM's. The SLS also uses a 3.11 final drive compared to the STS 3.71, so there will be engine/transmission management differences there, too. AJ, ewill3rd, or tateos have a better handle than I on swaps between the two different models.

Harry Yarnell
09-13-08, 08:35 PM
I didn't mention I'll swap the tranny also...

09-13-08, 08:36 PM
If I recall the Guru correctly, I believe the only difference is the intake cam (aside from the final drive of coarse).

09-15-08, 02:07 PM
Does your radiator not have the oil cooler in the right tank? If not, you COULD just get a new radiator - they're only around $200 on e-bay, and I think the engine oil cooler it is a good thing to have.

09-18-08, 04:02 PM
Make a cheap oil cooler with an old from a junk yard or old AC condensor. Here is where I got the idea and thought to myself, "why didn't I think of that? All these years paying ridiculous amounts for a 'oil cooler.'"


Harry Yarnell
09-18-08, 04:35 PM
Some Buick's and Cadillac's have an additional trans cooler in front of the condenser. Better to use this as an engine oil cooler than the internal oil cooler in the radiator.

09-18-08, 04:54 PM
BUT, the oil coolers in the Northstar radiator right side (hot) tank are designed specifically to keep the lube oil at or above the thermostat operating temperature. Why ? To allow the lube oil to quickly heat to a temperature which is conducive to good oil flow and at the same time be able to boil off acids and moisture into vapor which is then extracted from the crankcase by the PCV (!) system and burned in the combustion process.

Running your lube oil too cold is death on an engine. .........and, regardless of a PCV system, creates hellish amounts of real sludge in the rocker/cam covers, primarily.

In this day and age most engines are carefully designed to run the lube oil in a specific range of temperatures. The mistaken "mod" of additional oil coolers in fact decreases overall oil performance and shortens engine life. The myth that today's multigrade oils do not feel "oily" enough is pure fantasy at room temperature and would scare the heck out of you if you messed with it at 215 degrees.

09-18-08, 09:09 PM
I could not have said it better than Sub.

I added a trans cooler (in front of the AC condenser) to my ETC, back when the TCC wasn't working - I reasoned that the slip caused higher trans fluid temps, which it seemed to do. Anyway, I added it before the one in the rad, not after. That way, the temps wouldn't tend to go too low.