This seems really weird. Why would they interpret the temp to display when they know the actual temperature I wonder?
Oil Temperature problem
- Thread starter Vetracr
- Start date
This seems really weird. Why would they interpret the temp to display when they know the actual temperature I wonder?
Well, diagnostic tools and logging tools show separate parameters for oil temps and Engine coolant temps. The oil temp dash gauge is receiving its data from the DME the same as you would get using an OBDII tool. The ECT or Engine Coolant Temp parameter has nothing to do with the oil temp parameter they are completely separate on the DME.
Here is a screen shot of my ECT parameter running at normal operating temps. Oil temps is about 35°f higher on the dash display which would be identically the same temp if I was to monitor it via with any OBDII tool. I dont monitor it on MHD cause its already on my dash. When ECT starts hanging around oil temps its an indication the water pump is about to go, thats why I have it monitored in MHD.
From the electrical schematics it appears for both the N52 and N54 engines, the oil condition monitor connects to the DME through the BSD serial interface. The water?/oil? temperature sensor on the oil filter housing is a variable resistor read by the DME so both sensors input to the DME. AS you have the diagnostic tools can you monitor the scan tool oil temperature and water temperature and then compare them to the dash display?
Its all due to the new technology called the "heat management system" by BMW which incorporates lots of variables to control the oil and water flow through the engine like the variable flow oil pump, the electronically controlled water pump, etc.
Oh you mean dumb complicated shit that is just going to fail prematurely unlike tried and tested solutions?
Right on brother. I've been building race cars for 50 years. I thought I'd seen it all until I started working on a BMW. The Germans never heard of the kiss principal, a basic tenet of American engineering, i.e., "keep it simple stupid".
Just finished my track day at Ningbo Int'l Racepark. I did some temperature logging with the DCT cooler and aux oil cooler pumps both activated:
https://datazap.me/u/asbjoern/2nd-track-session-0?log=0&data=5-19-21-26
During this session the oem oil cooler fan was NOT turned on. I wanted to do another session with it ON to compare, but unfortunately the day ended with a boost leak and half check engine light (30ff).
Results:
When I study the log, it looks like the oil temp is slowly climbing throughout the session. Coolant temp does not start to climb until the oil temp passes 120C / 250F, but I am not sure if I can conclude anything based on that.
My only conclusion is that air flow to the oem oil cooler, and in particular the additional oil cooler is not sufficient to keep the engine oil temp stable. While I have not tested my oil cooler fan yet, I will go ahead and assume the additional oil cooler also need fans. So I am installing another set of push-pull fans on the additional oil cooler, and making it so both fans turn on at the same time as the pumps.
I also conclude I do not need to worry about DCT cooling or air intake cooling ever again.
Summery of what was tested today:
OEM oil cooler with fan turned off
CSF Coolant radiator
VSRF race intercooler (covering some of the coolant radiator)
SSP dct oil cooler with pump (covering some of the coolant radiator)
Additional oil cooler with no fan
The weather was 25C / 77F and humid 85%. I'm running 0W40 Mobil 1, and coolant with reduced amount of anti-corrosion and water wetter.
Sport cooling selected in MHD
https://datazap.me/u/asbjoern/2nd-track-session-0?log=0&data=5-19-21-26
During this session the oem oil cooler fan was NOT turned on. I wanted to do another session with it ON to compare, but unfortunately the day ended with a boost leak and half check engine light (30ff).
Results:
- My car reached peak coolant temps of 110C / 230F and peak oil temps of 130C / 265F in less than 5mins. This is disappointing, but at least below any limp mode set points.
- Transmission temp never exceeded 90C / 195F and iat never exceeded 50C / 125F. I believe this is brilliant.
When I study the log, it looks like the oil temp is slowly climbing throughout the session. Coolant temp does not start to climb until the oil temp passes 120C / 250F, but I am not sure if I can conclude anything based on that.
My only conclusion is that air flow to the oem oil cooler, and in particular the additional oil cooler is not sufficient to keep the engine oil temp stable. While I have not tested my oil cooler fan yet, I will go ahead and assume the additional oil cooler also need fans. So I am installing another set of push-pull fans on the additional oil cooler, and making it so both fans turn on at the same time as the pumps.
I also conclude I do not need to worry about DCT cooling or air intake cooling ever again.
Summery of what was tested today:
OEM oil cooler with fan turned off
CSF Coolant radiator
VSRF race intercooler (covering some of the coolant radiator)
SSP dct oil cooler with pump (covering some of the coolant radiator)
Additional oil cooler with no fan
The weather was 25C / 77F and humid 85%. I'm running 0W40 Mobil 1, and coolant with reduced amount of anti-corrosion and water wetter.
Sport cooling selected in MHD
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Well, in my case, they certainly dont help with airflow when turned off haha.
What I installed was two water proof 12V/4A high speed fans mounted in a push-pull configuration. Ie almost 100W of fan power. They cover a little more than half of the surface area of the oem oil cooler.
I will try and return with new logs some time in July
@Vetracr if you are on Facebook, 3DM Motorsport created a new Facebook group - E9x/E8x Track Cars.
Filippo
Filippo
May I ask if you have a thread with more photos of the dct cooler install?
I'll try to find this cooler. I have a 72 row setrab I was going to use for this purpose... But after consulting some people and now seeing your results, would you consider the fact that perhaps we've got our setups backward?
The engine coolant and oil are linked in terms of heat dissipation. Turning that dct cooler into an engine oil cooler would make more sense because they cool together, and transmission heat isn't being introduced into the engine coolant circuit.
This means the dct cooler would need to become more complicated and use one or both side duct venting areas.
This is my current plan anyway, I just need to see if the trans fluid pressure is sufficient to make a few extra bends to see both side coolers.
I posted some pictures in my build thread here
https://bmw.spoolstreet.com/threads/z4-track-ready-sleeper-build.3026/page-3
In my understanding the dct oil is both heated and cooled through a heat exchanger to the engine water cooling system. Our cars do not come with separate dct oil coolers from factory. Also I did not disable this heating/cooling function software wise.
So I would assume that keeping the dct from overheating takes some load off the engine cooling system.
Curiously the M4 GT4 uses the standard S55 coolers, except for the transmission cooler, which is upgraded to the M5/6 version.
BTW do we know if the 5 series has less/no limp mode issues? I read it has a huge N54 oil cooler from factory.
Anyhow, I still need more time to optimize my car's cooling and do some more logging. I will definitely share what I find when ready.
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Yes, in stock form this is the case but you negate some of that benefit by putting the trans cooler in front of the radiator. The engine oil and coolant temps are linked for obvious reasons, cooling one will cool the other so I figured there would be more synergy by putting them together. This is actually advice I received from @Dusty Waterfall while trying to construct my trans cooler as you are many months ago, and I'm coming back around to it.
Your DCT oil temps don't seem to be challenged, so it seems like the oil could benefit a bit more from that central, premium location.
I posted a quick update over in my build thread, and just wanted to mention the conclusions here as well. I tried running the fans while practicing drifting, and they did not keep the oil temp from rising. I then removed them completely and did some laps at Ningbo Racepark in +100F heat. Car hit 116C coolant and 134C engine oil on lap three, which means my coolant is 1C from engine power reduction start, while oil is 15C from it.
This leads me to conclude that I need to add an aux water cooler as next step. Now the only question is where to put it... There is no space left anywhere. Should probably go behind the aux engine oil cooler.
I suspect there is also a significant difference between the stock bumper and m-sport bumper - BMW doesn't design just for looks. When I get back home, Asbjørn, we can work some comparison measures together to see what that my tell us. All the fans and cooling fins in the world can't do much in an enclosed environment with a limited open area.
Filippo
Filippo
Alright I went ahead and ordered below. If the bumper really matters, I am about to find out. Reporting back with new temperature logs in one month's time or so.
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