Oil Temps Too Low with New Oil Cooler?

[LaszloToth]

Replaced the CSF Racing rad with a CSF oil cooler combo rad in my '11 STi sedan and although this will work brilliantly at the track I am concerned that the oil temps are too cold for street use. Car is stock with oil temp monitoring, AOS and this big rad with an integrated oil cooler. Objective is reliability at the track.

Measured at the sandwich plate with an Auto Meter electric gauge, oil temps were 225F max with the CSF Racing rad at the track. This is good.

The CSF oil cooler combo rad has a thermostat sandwich plate set at 75 - 82C +/- 2C. Converted to imperial this is 167 - 180F, which is basically coolant temps.

Now highway temps are 167F in (13C ambient) and 180c in city driving, and I'm concerned that this is too cold for winter driving.

It looks like the industry standard thermostat setting for external oil coolers is 185F but I'm learning that the target temp for oil in a street driven car should be between 215 and 240F.

Should I be concerned about these oil temperatures for the winter in Canada?

 

[69GTX]

It's "possible" anything under approx 170-180 deg F oil temp might mean less than full activation of your oil's additive package. You could always block some of your radiator's front opening in the winter. I used to routinely do that with some of my performance cars years ago that would run too cool in winter otherwise. With a 167 deg F coolant temp, your oil temps could be 10-30 deg higher.

 

[maxdustington]

Originally Posted By: 69GTX
It's "possible" anything under approx 170-180 deg F oil temp might mean less than full activation of your oil's additive package. You could always block some of your radiator's front opening in the winter. I used to routinely do that with some of my performance cars years ago that would run too cool in winter otherwise. With a 167 deg F coolant temp, your oil temps could be 10-30 deg higher.


You see large trucks with the grille covers all the time here, you should identify where the oil cooler is located in the radiator and block that part off if that is possible. You might even consider removing whatever blocking you devise only for track use, idk what your tune or driving style is though. I would be wary about anything strapped to the radiator due to vibration. I think the best solution would be some type of thermostat, I've seen them mentioned for use with auto trans coolers. I guess the application is for a tow vehicle that needs the cooling, but not all the time. That sounds pretty similar to your application.

 

[Johnny2Bad]

You can try installing a different temperature valve; Mocal sells them in an optional high temperature version (95C / 205F). That would still open at your track oil temperatures, it might even help since rapid warmup to operating temps is an advantage in any engine.

http://mocalusa.com/thermos.htm

Another option would be to install a water / oil intercooler as fitted on some OEM vehicles (my Miata uses one, VW uses them a lot, etc). These warm up the oil temperature to coolant temperature rapidly to assist in vehicle warmup. The warming action is greater than the cooling action, although there is some cooling action (temperatures of oil and coolant are closer to each other than without the intercooler). Maybe "intercooler" isn't the correct term as used by manufacturers, but if not you can probably figure it out.

It's fairly common here to block off air into the cooling system in winter; in my Miata if I don't cover the radiator with cardboard it only reaches operating temps in stop-and-go traffic; as soon as I get onto expressway speeds the temps fall rapidly below proper coolant temperature (the gauge drops to below 180F in about five minutes). But Toronto is much warmer than here, I am not convinced it would be a good idea with your typical ambient temperatures. You could try a partial block if you want, but I personally would explore the other options I mentioned. You don't want to over-heat with a blocking mechanism.

 

[LaszloToth]

That's a great suggestion, Johnny. Wish I could just change the t-stat that's part of the oil cooler circuit in the CSF combo rad to a 205 or 215 F item instead though.

 

[antonmnster]

My 335 lives around 235F, and the t-stat to the external cooler doesn't doesn't open until like 250F, which it's done maybe twice in the last 80,000 miles. I'd go hot.

 

[Merkava_4]

Originally Posted By: antonmnster
My 335 lives around 235F, and the t-stat to the external cooler doesn't doesn't open until like 250F, which it's done maybe twice in the last 80,000 miles. I'd go hot.


Are you referring to oil temperature or coolant temperature ?

 

[SHOZ]

I had a cooler/heater attached to the oil filter mount for a while. It did cut in half the warm up time. It also used the hottest coolant in the motor (coming out of the turbo after the head)

 

[antonmnster]

Originally Posted By: Merkava_4
Originally Posted By: antonmnster
My 335 lives around 235F, and the t-stat to the external cooler doesn't doesn't open until like 250F, which it's done maybe twice in the last 80,000 miles. I'd go hot.


Are you referring to oil temperature or coolant temperature ?


Oil. There is no coolant temp gauge since the ECU varies it between 205-225F.

 

[LEADED]

Do you mean a heat exchanger like on Ford Ecoboost blocks .

 

[LaszloToth]

Subaru's have an OE oil cooler at the filter housing, which is liquid to liquid. Pictures of OE item below. This helps heat the oil upon startup as well.

The CSF Combo rad is also a liquid to liquid type as it's integral in the bottom of the radiator, but this rad oil cooler loop has a thermostat in it. Effectively, the CSF Combo rad will keep oil at coolant temps unless the oil cooler thermostat has a higher-than-coolant set point.

I'd like the oil to run above 212 F, so that's why they oil cooler's 170 F set point seems too low. It's likely a design for off road only (race), and not street.