OEM Oil Cooler Kit and Installation DIY

[7 skulls]

I believe the Cusco oil cooler bypasses the rad, running hot coolant from the engine through the oil cooler and back to the engine coolant (cool) intake. During steady state highway driving, I see 92 C on the coolant (OBD port) and 87-92 on the oil (OBD port). But driving hard with the rpm above 4000, I get less than a mile before oil temps top 116 C. When I back off the rpm, oil temps cool down fast but as others have said, this oil cooler makes no difference to max. oil temp.

[Harey]

Originally Posted by SkiRideDrive

The canyon run temperatures above were absolute worst case scenario, driving the car very hard on a very steep and very tight road. I have included two more comparison graphs below. They are on a more typical canyon road, predominantly third gear. These runs however, also utilize everything the car has to give. A more casual canyon run will likely have different results.

These runs (east grade) were also done very soon after running the very demanding road above (south grade). You may notice that the oil temperatures on the WITH cooler logs are decreasing. This is the cooler doing its job and dropping the oil temperature which were elevated by the very aggressive road driven prior. In the logs above, you will notice approximately a 11 degree max difference in oil temperature. In the more conventional canyon road below, you will notice after the cooler stabilizes the oil temperature, a more significant 20 degree drop or more. I think this is more representative of what a typical canyon driver will see, if not more, since this road is still being driven quite aggressively.

More Typical Canyon Run without Cooler



More Typical Canyon Run WITH Cooler


I hope this helps, please let me know if you have any questions.

Firstly I want to say thanks heaps for doing this write up and going to the effort of getting this data and sharing it with us.

It is very difficult on the street to get an exact comparison I understand that. I think this second example it not super accurate as the example with cooler has a lower coolant temp. If anything the coolant temp with the cooler should be below or at the very least equal to without the cooler.

I think the first example is more beneficial and while it is not a huge difference i think 10 degrees is still a nice drop and you can see without the cooler it keeps rising where the cooler keeps it levelled out.

[jflogerzi]

One thing to add is if you have a tune you can request to have your rad fans run at lower temps which might help keep things a bit more cooler and and allow for quicker cool downs

[majixmatrix]

What options exist for including a pressure and temperature sensor in-line with this setup? I imagine you can't run a typical sandwhich plate along with the oil cooler?

[jflogerzi]

One question. I am about to install this cooler along with doing a fresh oil change. Was is needed to burp the coolant... and second does it matter which port under the TB do the hoses go to? Or does it not matter

[Bonburner]

Originally Posted by jflogerzi

One question. I am about to install this cooler along with doing a fresh oil change. Was is needed to burp the coolant... and second does it matter which port under the TB do the hoses go to? Or does it not matter

If you want to be lazy with the burping:
Cut the tubes to desired lengths
Prefill the tubes & cooler with coolant
Plug both ends for easier installation of cooler to engine,
Plug in the ends of the tubes to respective ports (you can keep the ends of the tubes at equal heights to minimize coolant spill; I suggest you plug in the bottom port in first)

[jflogerzi]

Originally Posted by Bonburner

If you want to be lazy with the burping:
Cut the tubes to desired lengths
Prefill the tubes & cooler with coolant
Plug both ends for easier installation of cooler to engine,
Plug in the ends of the tubes to respective ports (you can keep the ends of the tubes at equal heights to minimize coolant spill; I suggest you plug in the bottom port in first)

Thanks for the info. Does it matter which hose goes into which port under throttle? IE one is an inlet and one is an outlet...

Sent from my ONEPLUS A5010 using Tapatalk

[Bonburner]

Originally Posted by jflogerzi

Thanks for the info. Does it matter which hose goes into which port under throttle? IE one is an inlet and one is an outlet...

Sent from my ONEPLUS A5010 using Tapatalk

Honestly, I've wondered that too and I tried to find diagrams of coolant flow, no luck.

I've also tried to look for the 14+ Forester and the 15+ WRX coolant flow diagrams (very minimal effort, got lazy) and didn't find anything.

Honestly, I doubt it matters.

[Turdinator]

Just an FYI for anyone getting this kit, as it is barely mentioned in the original post. The cooler itself has a 3/8" and 1/2" barb while the throttlebody has 5/16" barbs. The hose supplied is 3/8" so it only fits one of the four barbs properly. You can probably make it work but I chose to get some adapters and short lengths of the correct size hose.

[jacjac3]

What oil weight did you use for this measurement?

[86zn6]

Just start to look into this oem cooler, does anyone know the length of the coolant hose? Is 1m enough?

[mrjj]

Originally Posted by 86zn6

Just start to look into this oem cooler, does anyone know the length of the coolant hose? Is 1m enough?

I think hose length is covered by this install video:

[86zn6]

Originally Posted by mrjj

I think hose length is covered by this install video:

Thanks. 24" and 30".
I wonder what degree should the hose be rated? would it go over 100C or 212F since it's just carrying coolant?

[weederr33]

Originally Posted by 86zn6

Thanks. 24" and 30".
I wonder what degree should the hose be rated? would it go over 100C or 212F since it's just carrying coolant?

If you get good brand heater hose, it should be fine. I'd add some sort of thermal sleeve to protect it from the engine block heat.