Low oil level message but sump full 06 S60 R

[erikv11]

For the past week or so the car gives this message after about 10 minutes of driving, even though the sump level is at the top of the dipstick mark when the engine is off.

- "Low oil level stop engine" message and red triangle
- Definitely comes on only after warmup, not when the engine is cold. If I stop the car then start it up while still warm, comes on more quickly, within a few minutes.
- When it comes on, if I pull over and check the dipstick with the engine running I do not find bubbles on the dipstick - doesn't seem to be pulling air due to bad pickup o-ring(s).
- Oil was last changed in August so about 8 months ago. Car wasn't used much this winter, only 1600 miles since the oil change.
- Running Mobil1 0w-40 synthetic in this car, until I use it up and switch over to Rotella T6 5w-40.
- Engine is running well.

Any thoughts on or experience with solving this one? If it is a sensor or wiring issue it seems to be linked to heat. Unless I get some insight, my next tack may be to blindly replace the oil.

[- Pete -]

I’d be willing to bet the oil level sensor just needs to be cleaned. There was a DIY a while ago. I’ll paste it if I find it before you do.
Next oil change just pull the sensor out of the pan & clean it up. Should work fine after cleaning. They’re expensive & not a lot of T5 or R’s in the scrap yard to rob one off of.

Edit: here ya go

viewtopic.php?t=88441

[SuperHerman]

Disconnect the sensor and see what happens. You should get the warning right away. Not sure how the sensor works, but if you have a VOM I am sure you can do some testing - both cold and hot when it signals a fault.

How much is the sensor? May make more sense to pony up the dollars and order one. Another forum member had an issue with some sensor, don't recall which one, and it ended up being a cracked sensor. I suppose you can get under there and inspect it while your are unplugging it for testing purposes.

[erikv11]

Thanks Pete and Herman. I will be lazy about it until the next oil change or until it drives me nuts.

The sensor is $200 - $250 new so no way replacing it until several fixes are tried. And/or junkyard options exhausted.

[erikv11]

After about two weeks the message stopped showing up, haven't seen it for a couple weeks now. Perhaps some critical piece of debris dissolved or dislodged. I'll still clean the sensor at the next oil change.