Does anyone know why only forester engines have the water cooled oil coolers?

Hm not sure, actually I didn't know they came with them. I know the H6's have that setup. Must be in the Forester they saw the need to buffer the oil temp against the coolant temp.

Towing?

Ah ok maybe part of a towing package...hm some research on cars101.com might show it.

I dont think it was a package thing. Every forester 98+ i've worked on has them. I've been adding them to the engines I rebuild for added longevity.

The have aluminum thermostat housings with an added snout > hose runs to oil filter area where the cooler bolts where oil filter goes with a longer tube. the cooler has two snouts: one to the thermostat housing one to a snout that threads into a water jacket that has a 14mm allen plug. unthread plug then thread in snout and voila>>> oil cooler

Automatic and Turbo Foresters have them. N/A 5 speeds did not.

'91 Turbo Legacy's had them as well (but later years did not). They only came as a 5 speed. It was initially a turbo thing - Forester's probably got them for light towing. Frankly I would rather have a real oil cooler rather than one that is tied to coolant temp. Not an ideal system IMO. Better than nothing though.

 

GD

It might also be there to *heat* the oil in cold climate areas, to prevent sludging.

 

Dave

i looked at the opposedforces.com/parts parts site for forester SOHC engines and it indicates that the auto trans got them and the manual trans did not.

That's true. I think that type of oil cooler/warmer is great if the vehicle is being used for a lot of short trips to help the engine oil get up to around 180F faster to avoid condensation build up.