Overheating while running A/C

[0-60motorsports]

which pulley did you have on?

BHS pulleys.

So here’s my theory after test driving the car over a good distance today and in traffic in 38-41c temps at 5:30pm (sun sets at around 6:30pm).

The car seems to be controlling the water temps much better after removing BHS pillows and going back to stock pillows BUT I see the oil temps are not getting under control for some reason. What I think is that the Bimmerworld oil cooler I have from 2012 might have failed internally as it is clean from the outside and gets jet washed every few weeks so sand or dust is not an issue. No leaks either.

I do not think it’s the oil level and temp sensor either. I find getting the cars oil temps to come down from almost near the third dot is very hard which is what it is reaching to in these conditions. The car never used to do this, only on track which is normal.

I am going to look for my Oe oil cooler and install it and test the car and report back.

If it fixes the problem Options are stick with OE oil cooler or get mishimoto oil cooler (most budget friendly).

Tomorrow I’ll be test driving the car in traffic and highway between 12 noon and 2pm as it is hottest then and temps are around 45c. Will report back with findings.

In the time I have owned the car since 2006 I have never had this issue. It’s been perfect so let’s see....


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[eacmen]

BHS pulleys.

So here’s my theory after test driving the car over a good distance today and in traffic in 38-41c temps at 5:30pm (sun sets at around 6:30pm).

The car seems to be controlling the water temps much better after removing BHS pillows and going back to stock pillows BUT I see the oil temps are not getting under control for some reason. What I think is that the Bimmerworld oil cooler I have from 2012 might have failed internally as it is clean from the outside and gets jet washed every few weeks so sand or dust is not an issue. No leaks either.

I do not think it’s the oil level and temp sensor either. I find getting the cars oil temps to come down from almost near the third dot is very hard which is what it is reaching to in these conditions. The car never used to do this, only on track which is normal.

I am going to look for my Oe oil cooler and install it and test the car and report back.

If it fixes the problem Options are stick with OE oil cooler or get mishimoto oil cooler (most budget friendly).

Tomorrow I’ll be test driving the car in traffic and highway between 12 noon and 2pm as it is hottest then and temps are around 45c. Will report back with findings.

In the time I have owned the car since 2006 I have never had this issue. It’s been perfect so let’s see....


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In my experience new OE oil cooler will likely outperform the aftermarket ones from a cooling perspective. The only advantage of an afternarket oil cooler is the increased capacity which is a marginal benefit.

Buy it from FCP and replace when it gets dirty.


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[High.miles.big.smiles]

Check your ambient air sensor, oil temp references is, if it is reading incorrectly, oil temps will be higher

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[0-60motorsports]

Check your ambient air sensor, oil temp references is, if it is reading incorrectly, oil temps will be higher

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Yeah I suspected that too so I changed it to a new one a few weeks back. Might relocate it to the the grill in the bumper to get a more accurate reading.


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[0-60motorsports]

I am going to look tomorrow again for my OE oil cooler and if I can’t find it will post up a new WTB thread on the sales section. The newest BW oil cooler looks like a better design but the cost is $800+ and I am not looking to spend that much right now.


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[M3steve]

Oil temp can influence coolant temp as well. Make sure oil cooler is clean.

I'm also chasing an overheating issue and am curious to learn more about this.

If I'm reading right, this seems to imply that rising coolant temps can be an adverse effect of poor oil cooling. Is that the idea (i.e. hot oil > hot engine > hot coolant)?

eacmen or anyone, can you expand on the relationship between the oil cooler/oil temperature and the cooling system?

[eacmen]

I'm also chasing an overheating issue and am curious to learn more about this.

If I'm reading right, this seems to imply that rising coolant temps can be an adverse effect of poor oil cooling. Is that the idea (i.e. hot oil > hot engine > hot coolant)?

eacmen or anyone, can you expand on the relationship between the oil cooler/oil temperature and the cooling system?

Yes hot oil leads to the cooling system needing to work harder to cool the engine. Everything is connected to one another.

If you're having serious overheating issues will better oil cooling help? No

But if you're getting marginal increases in water temp trying to improve oil cooling may help alleviate the issue.


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[S14]

In my experience new OE oil cooler will likely outperform the aftermarket ones from a cooling perspective. The only advantage of an afternarket oil cooler is the increased capacity which is a marginal benefit.

What makes you say that?

[eacmen]

What makes you say that?

I have had 95k mi OEM, new OEM, CSF, and C&R. The new OEM performed the best on track in hot ambient temps.

Also the OEM ones seem to have less QC issues than the aftermarket based on extensive threads on the old forum.


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[0-60motorsports]

So I still haven't found my OE oil cooler, still looking though, BUT in the meantime. Went to start the car and warm up at idle and the outside temps are around 110f in the shade and went all the way up to 119f at the end of our journey.

I start the car and turn on the AC and wait for my wife, by the time she comes down in 10-15 mins the car has already passed the half way mark on the coolant temp gauge and the oil is only between the 1/4 an 1/2 way mark. All the way to the destination which was around a 20-30 mins drive the coolant temps would be erratic, 91c at the lowest to 98c once we reached the destination which was the shop where the car is worked on. My wife was observing all this and i had told her about the high oil temps but yesterdays drive the oil temp only went a tiny tiny bit past half which is normal for our region.

So Fellas, it might not be the oil cooler, God knows what it is because I am highly frustrated right now and cant think straight. I am thinking coolant temp sensor.

Keep in mind as soon as I press the switch to deactivate the AC Compressor temps fall in 5-10 secs LOL. Issue is as stated only with AC on and when outside temps are over 104f

[eacmen]

If you don't have a data logger maybe try and use this trick to get a numerical coolant temp readout:

https://youtu.be/wjKt0ZQBV2U

If its the sensor it might display erratic behaviour. But I would think the ECU would throw a code if the inlet coolant temp and outlet don't jive.


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[0-60motorsports]

If you don't have a data logger maybe try and use this trick to get a numerical coolant temp readout:

https://youtu.be/wjKt0ZQBV2U

If its the sensor it might display erratic behaviour. But I would think the ECU would throw a code if the inlet coolant temp and outlet don't jive.


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I will try that and see how it compares to the bluebus readout. Thank you.

[eacmen]

I will try that and see how it compares to the bluebus readout. Thank you.

Didnt realize you had bluebus data. The dash readout wont be any different than what you get from bluebus. Do the coolant temps (inlet/outlet) from bluebus make sense?

[0-60motorsports]

It just shows the coolant temp. One temp, not inlet and outlet.

[S14]

So Fellas, it might not be the oil cooler, God knows what it is because I am highly frustrated right now and cant think straight. I am thinking coolant temp sensor.

Keep in mind as soon as I press the switch to deactivate the AC Compressor temps fall in 5-10 secs LOL. Issue is as stated only with AC on and when outside temps are over 104f

My symptoms are the same as yours, only when the AC is on and I'm driving on the freeway at sustained 3k or greater RPM and Pheonix AZ heat is over 4k. I've replaced the radiator with a CSF one and the oil cooler with a CSF, run both fans, just the aux fan, just a mishimoto electric fan and nothing changes. The temps are not congruent, cluster says it's over heating, cluster test shows a higher readout than the OBD data, laser IR temp gun shows nothing in the coolant system is overheating.

This guy on bimmerforums seems to have similar issues that I'm experiencing, and it kinda sounds like your issue too. In post #16 he mentions that replacing one or the other sensor made his INPA reader show some odd readings, but when both werer replaced, the car finally showed the correct temp.

https://www.bimmerforums.com/forum/s...6#post30503676

It's weird that last year (although without track time) never saw the needle GET to 3/4 high, yet here we are this year. REALLY odd was that I was not seeing coordinated readings (cluster menu 7.0, infra red readings, and scanner data stream as well as oil temps) until BOTH temp sensors were replaced. But, a win is a win is a win !!

My water pump and t-stat/hoses/radiator were all replaced a little over 40k ago. Before I throw $1k in parts at the problem, I'm going to replace both sensors and re-bleed the coolant system. Also, I bleed the CSF radiator "incorrectly" according to bimmerworld (those guys are awesome), I'll try bleeding the CSF radiator per their instructions

http://news.bimmerworld.com/csf-trip...airing-it-out/