Monitoring Engine Temp - no oil temp

[jbailer]

The biggest two will be coolant temp and oil pressure.

If you see your coolant going way up then so is your oil.


Some quick numbers

At a 100f trackday at its hottest I had coolant temps at
225F

275F for oil temp via Cobb and 218F for oil temp with my own gauge.

Wow that's quite a difference on the oil temp! With it that far off and being that high, I wonder if they were using CHT, trying to infer oil temp? I guess I could use ECT and that would be easy. I was thinking that the coolant would warm up faster than the oil because there is no water flow until the thermostat opens so the coolant would warm up faster. I'm not sure that's a good assumption though. I watched ECT and CHT once during a warm up and they stayed locked within 1* of each other until the thermostat opened. I would imagine the oil temp must be about the same. It just didn't show the oil temp hitting the beginning of the green area until 178*, when the thermostat opens so I guess I could just use ECT @ 178*.

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[xXANCHORMONXx]

Wow that's quite a difference on the oil temp! With it that far off and being that high, I wonder if they were using CHT, trying to infer oil temp? I guess I could use ECT and that would be easy. I was thinking that the coolant would warm up faster than the oil because there is no water flow until the thermostat opens so the coolant would warm up faster. I'm not sure that's a good assumption though. I watched ECT and CHT once during a warm up and they stayed locked within 1* of each other until the thermostat opened. I would imagine the oil temp must be about the same. It just didn't show the oil temp hitting the beginning of the green area until 178*, when the thermostat opens so I guess I could just use ECT @ 178*.

Yeah I believe the coolant temp will be your best bet honestly.

Running an extra gauge is easy though.

I had mishimoto a oil cooler which has built in ports for that reason. There's a few for sale from what I see.

 

[HeelToeHero]

275F for oil temp via Cobb and 218F for oil temp with my own gauge.

Of course the actual gauge will read lower with an oil cooler. The algorithm for calculating oil temperature wasn't designed considering an aftermarket cooler. The correct test would be an aftermarket gauge with no aftermarket cooler compared against the factory one.

 

[xXANCHORMONXx]

Of course the actual gauge will read lower with an oil cooler. The algorithm for calculating oil temperature wasn't designed considering an aftermarket cooler. The correct test would be an aftermarket gauge with no aftermarket cooler compared against the factory one.

Please, do not comment unless you have first hand experience with this car.

Have you spoken to Cobb about this? How about Ford Performance? Have you been inside the tuning software to see where it pulls its values and how?

I spent days figuring this out with the help of many people, some of which are still on this thread. What you are claiming is 100% false.

How do I know? Because I tested inferred oil temp vs my oil temp before adding the cooler.

 

[HeelToeHero]

Because I tested inferred oil temp vs my oil temp before adding the cooler.

Is that not what I just asked for? What were those values? Was the 275F versus 218F you referenced with NO aftermarket oil cooler (ie just the factory cooler)?

The post wasn't clear and earlier posts referenced the addition of a gauge with an oil cooler.

 

[SVO MkII]

I know this is a pretty old thread, but I could use a little more insight on this topic of oil temps. My oil temp was getting into the yellow range on the digital gauge during HPDE events. I thought the ECU was also pulling power when this occurred. After reading about this being an inferred temp, am I wrong in assuming that the ECU will pull power when this inferred temp gets too high? Also, it sounds like installing an oil cooler will have little to no effect on the inferred temp. Is this correct? This would make me feel a little better about the fact that my "inferred" oil temp didn't seem to change much at the track after installing a cooler.

 

[xXANCHORMONXx]

I know this is a pretty old thread, but I could use a little more insight on this topic of oil temps. My oil temp was getting into the yellow range on the digital gauge during HPDE events. I thought the ECU was also pulling power when this occurred. After reading about this being an inferred temp, am I wrong in assuming that the ECU will pull power when this inferred temp gets too high? Also, it sounds like installing an oil cooler will have little to no effect on the inferred temp. Is this correct? This would make me feel a little better about the fact that my "inferred" oil temp didn't seem to change much at the track after installing a cooler.

I rarely comment on the forums these days but yes you are correct.
Your eb is thanking you for that extra cooling.

 

[SVO MkII]

I rarely comment on the forums these days but yes you are correct.
Your eb is thanking you for that extra cooling.

Thanks for the reply. For clarification, was I correct on both issues, i.e., the ECU pulling power AND the oil cooler having no effect on the inferred temp? Thanks.

 

[HeelToeHero]

I know this is a pretty old thread, but I could use a little more insight on this topic of oil temps. My oil temp was getting into the yellow range on the digital gauge during HPDE events. I thought the ECU was also pulling power when this occurred. After reading about this being an inferred temp, am I wrong in assuming that the ECU will pull power when this inferred temp gets too high? Also, it sounds like installing an oil cooler will have little to no effect on the inferred temp. Is this correct? This would make me feel a little better about the fact that my "inferred" oil temp didn't seem to change much at the track after installing a cooler.

The effect on the inferred value depends on the effect on the values used to make the inference. So by taking the heat load off of the radiator the, that's going to make the CHT a little happier. Likewise, if the oil is cooler the pressure may be in a higher range. These MAY have a positive effect on the calculated oil temperature.
One should also consider that the inferred calculation is based on a formula in the stock configuration with margin applied. Changing inputs in the formula could have a negative effect as well.

 

[SVO MkII]

The effect on the inferred value depends on the effect on the values used to make the inference. So by taking the heat load off of the radiator the, that's going to make the CHT a little happier. Likewise, if the oil is cooler the pressure may be in a higher range. These MAY have a positive effect on the calculated oil temperature.
One should also consider that the inferred calculation is based on a formula in the stock configuration with margin applied. Changing inputs in the formula could have a negative effect as well.

My coolant temp never budges. I suppose if the actual oil temp is remaining lower, the pressure could remain slightly higher. And assuming oil pressure is one of the inputs for the inferred oil temp calc, it could help to keep it lower. However, the big question for me is whether or not the ECU initiates safety measures when the inferred oil temp is too high. If so, you could istall multiple oil coolers, keeping the actual oil temp extremely low, but the ECU will still activate limp mode based on a very false inferred temp reading. I'd like to know if/how the ECU uses the inferred oil temp.

 

[xXANCHORMONXx]

Thanks for the reply. For clarification, was I correct on both issues, i.e., the ECU pulling power AND the oil cooler having no effect on the inferred temp? Thanks.

Yes on both!

 

[HeelToeHero]

My coolant temp never budges.

Cylinder head temperature.

If you're getting the oil hot enough to approach the yellow the water and cylinder head are getting warmer than normal street driving.

 

[SVO MkII]

Cylinder head temperature.

If you're getting the oil hot enough to approach the yellow the water and cylinder head are getting warmer than normal street driving.

Read post #21

 

[SVO MkII]

Yes on both!

So adding the cooler is helping to protect the engine, but the ECU doesn't know this, so after a few hot laps, it will start pulling power. That sucks. I wonder if this parameter (limp mode based on inferred oil temp) can be deleted or modified with an aftermarket tuner, like a COBB?

 

[Radiation Joe]

All of you are barking up the wrong tree.

If you are concerned about failures associated with oil temperature, then the first thing you do is run Redline or an equivalent oil. The "red" zone on your gauges is set for average oil. If you have an oil that performs well at high temperatures, the red zone is less of a concern. If you are buried in the red zone, then you need to find a cooling solution. Fixating on getting values from your data logs is missing the trees for the forest.

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