Oil temperature oscillating

[SYT_Shadow]

My 2013 has done that since day 1. Bought new, only bmw 10w60 oil used, 5k mile change intervals

[kevintr]

Hi guys, has anyone found a fix for this??

[Locksmythe]

In my understanding, the analog needle is an approximation of an approximation. The actual oil temperature is a mystery, estimated by measuring the water temperature.

When curious about my gauges I have used an OBDII dongle with an app to view a digital gauge readout in real time for oil temp to validate what is happening. Perhaps you could borrow one from someone local if you don't have one already. Then you could see if there is an actual fluctuation or something wrong with the gauge. It might be loose wiring somewhere or may be that the temp sensor in your thermostat housing is fouled up. Mine was black and I think it is made of brass which should be pretty hard to corrode, but it was still gross.


I used this for digital gauges:
ScanTool 427201 OBDLink LX Bluetooth: Professional OBD-II Scan Tool for Android & Windows by ScanTool
Link: http://a.co/6G3Kxqm

[kevintr]

Originally Posted by Locksmythe

In my understanding, the analog needle is an approximation of an approximation. The actual oil temperature is a mystery, estimated by measuring the water temperature.

When curious about my gauges I have used an OBDII dongle with an app to view a digital gauge readout in real time for oil temp to validate what is happening. Perhaps you could borrow one from someone local if you don't have one already. Then you could see if there is an actual fluctuation or something wrong with the gauge. It might be loose wiring somewhere or may be that the temp sensor in your thermostat housing is fouled up. Mine was black and I think it is made of brass which should be pretty hard to corrode, but it was still gross.


I used this for digital gauges:
ScanTool 427201 OBDLink LX Bluetooth: Professional OBD-II Scan Tool for Android & Windows by ScanTool
Link: http://a.co/6G3Kxqm

Thank you for the reply Locksmythe. Could you kindly point out the location of this sensor? is it inside the thermostat?

By changing this sensor did it fix your problem?

[Locksmythe]

Originally Posted by kevintr

Thank you for the reply Locksmythe. Could you kindly point out the location of this sensor? is it inside the thermostat?

By changing this sensor did it fix your problem?

I didn't have this problem with my temp gauge, I actually was interested in the Tach and O2 sensor readings, but i happened to check the temp reading to see how it looked. The digital reading is a little more granular than the needle but it does not report degree by degree, it jumps in several degree intervals. I will have to look again to see the size of the unit.

The temp sensor is on the top of the thermostat housing, directly below where the air intake connects to the engine plenum on the front of the engine. Disassembly is required to get to it, so it is not a trivial experiement.

[asmazda]

Went to dealer and they did extended road test on my car. They claim it is normal to have a little oscillation when it is really warmed up and at idle or slow city driving. At freeway speeds I really don't notice it oscillating much but then again I need to keep my eyes on the road! LOL

[Ggeezer]

Dealer mentioned to me that it's normal. If there were any oil pressure issues, then it would trip some sensors and I would have gotten a check engine light.

[kevintr]

Originally Posted by Ggeezer

Dealer mentioned to me that it's normal. If there were any oil pressure issues, then it would trip some sensors and I would have gotten a check engine light.

Thank you for all the reply, seem like this is a on going problem, or not. It Just concerned me very much because ot never did this before. When i got the car, oil temp seem to stay dead at on spot 1-5 degree lower than the 210 mark. I just wanted to make sure nothing wrong and it wont lead to another problem.

Please if anyone else having this problem and found the right fix, please let me know. Thank you.

[kevintr]

For some reasons, I suspect a bad or inefficient oil pump that is not pumping enought oil for the engine causing metal contact friction to increase, therefore raising the engine temp. Is there a way we could test the oil pump? Maybe doing a oil pressure test?

[dparm]

Originally Posted by kevintr

For some reasons, I suspect a bad or inefficient oil pump that is not pumping enought oil for the engine causing metal contact friction to increase, therefore raising the engine temp. Is there a way we could test the oil pump? Maybe doing a oil pressure test?

If there was an oil pump problem, I would think that's flagged other ways (oil pressure warnings, VANOS errors, etc).

[65fastback]

Ill join the party....i have owned my 2013 for 8 months now and thought it was "normal" it has had this type of temp fluctuation since day 1 of ownership, and ill add more to this deal...just had all 4 vanos solenoids and RB replacement and still does it.

[M3 n X5M]

Originally Posted by kevintr

Hi guys, has anyone found a fix for this??

The thermostat was replaced in mine and this same issue went away.

[jmeek83]

I'm an original owner of a 2013 that's done this since day one - with both 10W-60 and 0W-40.

[Locksmythe]

Originally Posted by M3 n X5M

The thermostat was replaced in mine and this same issue went away.

I'm curious about this as I think it is a mechanical thermostat that just opens at the specified temp to cool the water in the engine. i wonder if a failing thermostat would open and close repeatedly causing water temp to vary rapidly. The oil temp is estimated from the water temp, so that would do it.

As I suggested before, you can check the OBDII output for the digital temp reading to see if that is indeed varying versus a broken analog gauge.

[Richbot]

I thought there was also an engine oil thermostat but I don't see it anywhere on the parts diagrams so I guess it just sortof runs through there whether we like it or not during warmup

[Bob123]

Hi Ggeezer,
Did you ever get your oscillating oil temp issue resolved?
My 2011 M3 started having the same issue about 3000 miles ago. (although my dash gauges are calibrated in Fahrenheit instead of celsius) The needle often moves from just above to just below the center 210 mark in 5 seconds or less
once the car has been driven 35 miles or more. You can easily see the black background between the needle and the 210 reference mark.

Regards,

Robert

[Matheus]

Mine does that since i bought it stock. Continued to do it after supercharged and RB change.

[yidgyi]

Mines done this since I bought it 3 years ago. Car never had an issue. I run motul 10w60 after I did my bearings 20k miles ago.

[keeeban]

Mine does the same, although not as fast. Checked for any codes - none. Running 10w60 Liquimoly

[MShift]

Hate to revive old threads, but I just had my engine replaced and it started doing this. Before the new engine, it sat rock steady just below the 210 line, now it oscillates between 205-215 and it almost seems independent of engine temp (checked with Carly). Did this issue get resolved? Anyone figure it out?
I asked my dealer and they said not to worry about it. Got about 30 miles on the new engine, no faults.

[Mr. Liu]

your fine dont worry

[MShift]

Originally Posted by Mr. Liu

your fine dont worry

It actually looks like it's beginning to stabilize. Temp was sitting under the 210 mark today fairly steady.