Oil level down at higher temp, to come up again

[Helmsman]

Hi guys, the oil sensor keep hazzle us, this was a new one to me after 7y ownership.

Car never drunk any oil between changes (5k). On a 500 miles weekend trip it suddenly went down one click from max and eventually another to mid bar. Decided to wait before topping up. After coming back home/cooling down, it was up at top again.
It was a fairly hot trip with a good 30C and I noticed the oil temp climbing from normal just under 100C to a needle above, maybe 105C.

The day after the meter comes to max (as Carly, 32.64). Puzzles me as never happened during 7y, anyone else experienced the sensor going crazy due to a few degress warmer oil (for hours)?

Cheers

[Davisca455]

For my car, it has always shown a different level between city driving and highway driving, and this behavior has been very consistent throughout my ownership.
Once the car is warm, in the city, I'll check the level from the stalk and it will show completely full.
Once I'm a few miles down the highway, I'll check it again from the stalk, and it will have dropped to 1/2.
Once I get back into town and drive around for a little while at low revs and stop and go, I'll check it from the stalk again and the level shows full again.
My theory is that when on the highway, with the engine at a sustained 3000-3500rpm, the oil in the reservoir is being suctioned out by the oil pump at a slightly faster rate than the oil can return to the reservoir, to be sensed by the level sensor.
Then once in town with the revs slowed, the oil pump is now suctioning oil at a slower rate, more closely to the rate it returns to the reservoir, and therefore shows an increased level.
I think this would also occur if the car had a dipstick, it's just that we would never check the dipstick while driving.
Just a theory.

[BayAreaE93]

I hate the e-dipstick. I have probably poured in close to 9.3L of oil and it still shows as only slightly above the halfway mark. I've decided not to add any more oil to avoid potentially overfilling it.

[MP0W3RD]

Is the the sensor throwing any codes? You will not receive any warning lights on the dash but it could be failing.

[Helmsman]

Originally Posted by Davisca455

For my car, it has always shown a different level between city driving and highway driving, and this behavior has been very consistent throughout my ownership.
Once the car is warm, in the city, I'll check the level from the stalk and it will show completely full.
Once I'm a few miles down the highway, I'll check it again from the stalk, and it will have dropped to 1/2.
Once I get back into town and drive around for a little while at low revs and stop and go, I'll check it from the stalk again and the level shows full again.
My theory is that when on the highway, with the engine at a sustained 3000-3500rpm, the oil in the reservoir is being suctioned out by the oil pump at a slightly faster rate than the oil can return to the reservoir, to be sensed by the level sensor.
Then once in town with the revs slowed, the oil pump is now suctioning oil at a slower rate, more closely to the rate it returns to the reservoir, and therefore shows an increased level.
I think this would also occur if the car had a dipstick, it's just that we would never check the dipstick while driving.
Just a theory.

Interesting. This was highway driving so I assumed the engine finally started to consume oil. After 300 miles one way the meter sunk one step. Level stayed there during the couple of days visis, while driving shorter trips. Half way on our way back home, meter sunk again now to half. Once back home, after an hour stop, the meter (+Carly) is back on full. This was Saturday, still full Sunday.
Weird, never seen but seems alright.

[Redd]

Have you all thought about replacing the oil sensor? My car is 10 yrs 140k kms on the original oil sensor and no issues at all. I'm referring to the oil level reading in the gauges, not iDrive. I find the iDrive reading less accurate.

[Helmsman]

Originally Posted by MP0W3RD

Is the the sensor throwing any codes? You will not receive any warning lights on the dash but it could be failing.

Nope codes, all good.

Originally Posted by Redd

Have you all thought about replacing the oil sensor? My car is 10 yrs 140k kms on the original oil sensor and no issues at all. I'm referring to the oil level reading in the gauges, not iDrive. I find the iDrive reading less accurate.

Haven't yet, at 83kkm so would have thought things are still ok. Strange difference between gauge and iDrive, those surely must get the exact same in data?