[DailyN54]

I have a Cobb AP v3 and noticed that my coolant temps seem to go as high as 220f when I first start driving around the car. However, once the oil temps gets to 230f the coolant temps drop down to 204ish. I do not have an oil cooler yet. However, it is my next mod. My cars engine was recently replaced with a motor that had 22k miles on it. New radiator, new fan, Hexon RR700 turbos, Hexon inlets, MMP outlets, VRSF fmic. I also notice that when the car has high ECT's the car is pulling timing. Is there a relationship between oil and coolant temps?

[bradsm87]

Originally Posted by DailyN54

I have a Cobb AP v3 and noticed that my coolant temps seem to go as high as 220f when I first start driving around the car. However, once the oil temps gets to 230f the coolant temps drop down to 204ish.

I do not know of, nor have I experienced coolant temp target lowering once the oil is warmed up. Coolant temp target can lower if you drive aggressively though. Could it be simply because you are babying it during warm-up like you should but then driving aggressively once the oil is warmed up?

Originally Posted by DailyN54

I also notice that when the car has high ECT's the car is pulling timing.

Quite a few people have noticed this including myself. I've also noticed it on other cars. Cooler engine means less knock. The next XDF update should include pretty much full control over coolant temperature.

[bluemonstr]

Recently I replaced my radiator. Before this, I was monitoring my coolant temps as I knew I was 'leaking' fluid. I had to order the radiator and was driving while waiting for the replacement.

Since that time, I got the radiator replaced and because of that have been watching how the car runs. I noticed that when the outside temps exceed 100 - the car runs MUCH cooler. Literally. Normally, with AC on my car runs on average at 208F. When AC is off, the car runs between 205-225. This is when it's 80-96ish outside.

However, when outside temps get into the higher 90's - 98+, the car runs on average 180-185f coolant temps. I was on a trip from Socal to Sacramento 2 weeks ago and noticed all this. I was watching my temps out of curiosity - knowing that the temps were higher than what I normally drive in for any extended period of time.

Anyways, that is what I noticed when it came to coolant temps. Also, in relation to your question. I noticed that while highway driving in these extreme (to me) temps, when the coolant was 180f the oil temps were about 220-230f. I figured this was how the car keeps itself cooler in the hotter temperatures. BUT I wish that it would always run around 180 or let us tune that in or something.

Anyways, hope this helps ya!

[bradsm87]

Originally Posted by bluemonstr

Recently I replaced my radiator. Before this, I was monitoring my coolant temps as I knew I was 'leaking' fluid. I had to order the radiator and was driving while waiting for the replacement.

Since that time, I got the radiator replaced and because of that have been watching how the car runs. I noticed that when the outside temps exceed 100 - the car runs MUCH cooler. Literally. Normally, with AC on my car runs on average at 208F. When AC is off, the car runs between 205-225. This is when it's 80-96ish outside.

However, when outside temps get into the higher 90's - 98+, the car runs on average 180-185f coolant temps. I was on a trip from Socal to Sacramento 2 weeks ago and noticed all this. I was watching my temps out of curiosity - knowing that the temps were higher than what I normally drive in for any extended period of time.

Anyways, that is what I noticed when it came to coolant temps. Also, in relation to your question. I noticed that while highway driving in these extreme (to me) temps, when the coolant was 180f the oil temps were about 220-230f. I figured this was how the car keeps itself cooler in the hotter temperatures. BUT I wish that it would always run around 180 or let us tune that in or something.

Anyways, hope this helps ya!

Correct. The DME targets lower coolant temp once ambient temp exceeds 32°C and a lower again coolant temp once ambient temp goes over 37°C.

[Miller335]

Originally Posted by bluemonstr

Recently I replaced my radiator. Before this, I was monitoring my coolant temps as I knew I was 'leaking' fluid. I had to order the radiator and was driving while waiting for the replacement.

Since that time, I got the radiator replaced and because of that have been watching how the car runs. I noticed that when the outside temps exceed 100 - the car runs MUCH cooler. Literally. Normally, with AC on my car runs on average at 208F. When AC is off, the car runs between 205-225. This is when it's 80-96ish outside.

However, when outside temps get into the higher 90's - 98+, the car runs on average 180-185f coolant temps. I was on a trip from Socal to Sacramento 2 weeks ago and noticed all this. I was watching my temps out of curiosity - knowing that the temps were higher than what I normally drive in for any extended period of time.

Anyways, that is what I noticed when it came to coolant temps. Also, in relation to your question. I noticed that while highway driving in these extreme (to me) temps, when the coolant was 180f the oil temps were about 220-230f. I figured this was how the car keeps itself cooler in the hotter temperatures. BUT I wish that it would always run around 180 or let us tune that in or something.

Anyways, hope this helps ya!

The water pump must be working like mad to accomplish that.
I've heard others say when going WOT the DME tries to drop the coolant temps to <200 also. Maybe related to what you're saying.

[DailyN54]

Originally Posted by bluemonstr

Recently I replaced my radiator. Before this, I was monitoring my coolant temps as I knew I was 'leaking' fluid. I had to order the radiator and was driving while waiting for the replacement.

Since that time, I got the radiator replaced and because of that have been watching how the car runs. I noticed that when the outside temps exceed 100 - the car runs MUCH cooler. Literally. Normally, with AC on my car runs on average at 208F. When AC is off, the car runs between 205-225. This is when it's 80-96ish outside.

However, when outside temps get into the higher 90's - 98+, the car runs on average 180-185f coolant temps. I was on a trip from Socal to Sacramento 2 weeks ago and noticed all this. I was watching my temps out of curiosity - knowing that the temps were higher than what I normally drive in for any extended period of time.

Anyways, that is what I noticed when it came to coolant temps. Also, in relation to your question. I noticed that while highway driving in these extreme (to me) temps, when the coolant was 180f the oil temps were about 220-230f. I figured this was how the car keeps itself cooler in the hotter temperatures. BUT I wish that it would always run around 180 or let us tune that in or something.

Anyways, hope this helps ya!

Thank you for your response. I noticed the same thing. I also notice that my coolant temps rise much faster then my oil temps. However, once my oil temps get to around 220-230f my coolant temps drop to around 204. I wonder if this is on purpose so that it can help bring the oil temps up quicker. Like you, I wish I can keep the temps around 185-190ish. Our cars run so hot. I hope someone comes up with a solution to keep temps a bit lower.

[bradsm87]

Originally Posted by DailyN54

I hope someone comes up with a solution to keep temps a bit lower.

It is coming very soon to the public XDFs for those that flash with MHD or BBFlash. I've been running lower coolant temp targets for about 9 months. It's very unlikely that Cobb will implement this.

[DailyN54]

Originally Posted by bradsm87

It is coming very soon to the public XDFs for those that flash with MHD or BBFlash. I've been running lower coolant temp targets for about 9 months. It's very unlikely that Cobb will implement this.

I ordered the cables for MHD as well. So the XDF file will allow this? Are you a beta tester?

[bradsm87]

Originally Posted by DailyN54

I ordered the cables for MHD as well. So the XDF file will allow this? Are you a beta tester?

I found the ambient temp thresholds for the cooler modes for IJE0S initially and passed the info on to jyamona. He has now also found the coolant temp targets for Normal, High and High+KFT modes. I believe that either him or Martial are in the process of porting the discoveries to all ROM versions before public release.

[_ink]

Originally Posted by bradsm87

I found the ambient temp thresholds for the cooler modes for IJE0S initially and passed the info on to jyamona. He has now also found the coolant temp targets for Normal, High and High+KFT modes. I believe that either him or Martial are in the process of porting the discoveries to all ROM versions before public release.

Are there any reasons why our cars are dialled in to run so hot from factory? Given that they had the option to set the thresholds etc..

The only thing I can think of is emissions?

[bradsm87]

Originally Posted by _ink

Are there any reasons why our cars are dialled in to run so hot from factory? Given that they had the option to set the thresholds etc..

The only thing I can think of is emissions?

A VERY marginal (probably not even measurable) improvement in economy and emissions. Totally not worth the performance loss.

Maybe to make rubber seals crack so they can sell more replacement parts?

[titium]

Originally Posted by _ink

Are there any reasons why our cars are dialled in to run so hot from factory? Given that they had the option to set the thresholds etc..

The only thing I can think of is emissions?

alot if it has to do with the extremely long oil change intervals. higher temps help with removing moisture from the oil as well as any fuel (which is higher due to DI).

now this part I'm only speculating based on my limited knowledge of chemisty.

combustion leads to the burning of sulfur producing sulfur dioxide this dissolved in water gives sulfuric acid. sulfuric acid in oil= lower tbn, low tbn = oil past its used by date.

by removing the moisture the so2 is able to be removed through the pcv system rather then staying dissolved in the oil.

coincidence that the oil temp sits just above the boiling point of water? I think not.

also important which many people forget is that oil temp and coolant temp are 2 different things when i logged my coolant temp on track it sat around the high 80s even though oil temps were getting up around 130.

[DR-JEKL]

Originally Posted by _ink

Are there any reasons why our cars are dialled in to run so hot from factory? Given that they had the option to set the thresholds etc..

The only thing I can think of is emissions?

Im sure I read that the high oil temps was due to bmw engineers wanting to minimise oil blowby, by vaporisation?

[DR-JEKL]

Originally Posted by titium

alot if it has to do with the extremely long oil change intervals. higher temps help with removing moisture from the oil as well as any fuel (which is higher due to DI).

now this part I'm only speculating based on my limited knowledge of chemisty.

combustion leads to the burning of sulfur producing sulfur dioxide this dissolved in water gives sulfuric acid. sulfuric acid in oil= lower tbn, low tbn = oil past its used by date.

by removing the moisture the so2 is able to be removed through the pcv system rather then staying dissolved in the oil.

coincidence that the oil temp sits just above the boiling point of water? I think not.

also important which many people forget is that oil temp and coolant temp are 2 different things when i logged my coolant temp on track it sat around the high 80s even though oil temps were getting up around 130.

Its sulphur, damn yankee spelling haha

But yes correct

[DailyN54]

Very interesting viewpoint for why the temps were kept so high. However, since these cars are getting older I am very interested in lowering both coolant and oil temps to help with the longevity of the motor and other components. I change my oil every 3000-3500 miles so if your theory is correct any benifits from the higher oil temps would be negated.

[N8N]

Originally Posted by bradsm87

Correct. The DME targets lower coolant temp once ambient temp exceeds 32°C and a lower again coolant temp once ambient temp goes over 37°C.

OK, I apparently have an opportunity to learn something here...

On all the (very old) cars I've personally worked on, the physical thermostat determines coolant temp, sometimes aided by a thermostatically controlled electric fan. e.g. you put a 195F thermostat in, your coolant temps typically sit about 205ish and the electric fan kicks in at some point above that to help bring temps down, but the temp is not adjustable.

This talk of DME coolant temp target - how is that dynamically achieved? Is the thermostat replaced by a solenoid or similar?

[bluemonstr]

Originally Posted by bradsm87

It is coming very soon to the public XDFs for those that flash with MHD or BBFlash. I've been running lower coolant temp targets for about 9 months. It's very unlikely that Cobb will implement this.

This will be awesome! I would very much like to be able to lower my temps as I do NOT adhere to the typical oil change schedule. I'm changing mine w/in 6k miles. So any heat 'benefit' is not there for me. lol

AND N8N - it would seem regardless of the 'hardware' in the car (in this case the thermostat for the radiator system), the COMPUTER system of the car (DME) can and will control the driving temperatures depending on the needs of the current situation. That is what I was noticing when the temperatures outside get above 100f. That the car actually drives cooler than normal.

[Jeff@TopGearSolutions]

Originally Posted by bradsm87

It is coming very soon to the public XDFs for those that flash with MHD or BBFlash. I've been running lower coolant temp targets for about 9 months. It's very unlikely that Cobb will implement this.

That's the first thing I'm doing once available with MHD. No reason to run this car so hot. 195F is perfectly fine.

My z06 has a 160 T Stat. It can't even get that low. In the summer it's about 190 and in the winter it's about 175-180. Perfect.

Originally Posted by _ink

Are there any reasons why our cars are dialled in to run so hot from factory? Given that they had the option to set the thresholds etc..

The only thing I can think of is emissions?

A majority of the reasoning is emissions.

[titium]

@bradsm87 what coolant temps are you targeting?

what do your oil temps sit at?

[bradsm87]

Originally Posted by N8N

OK, I apparently have an opportunity to learn something here...

On all the (very old) cars I've personally worked on, the physical thermostat determines coolant temp, sometimes aided by a thermostatically controlled electric fan. e.g. you put a 195F thermostat in, your coolant temps typically sit about 205ish and the electric fan kicks in at some point above that to help bring temps down, but the temp is not adjustable.

This talk of DME coolant temp target - how is that dynamically achieved? Is the thermostat replaced by a solenoid or similar?

It's a combo of electric water pump control, a thermostat working normally and sometimes a heating element in the thermostat to make it open below its opening temp.

[DR-JEKL]

One thing I've noticed also is that manual cars seems to run cooler water & oil temps (Well my car does compared to others with AT) which I believe may have to do with the MT having a slightly larger rad?

[bradsm87]

Originally Posted by titium

@bradsm87 what coolant temps are you targeting?

what do your oil temps sit at?

I target 95C coolant at normal ambient temps. Oil temp generally sits at 100C when fully warmed up.