Oil level drops from full to minimum after 15 min highway drive

[pb2707]

Originally Posted by nrubenstein

Warm oil expands, so it's not that. My assumption is that some oil stays in the head during sustained RPMs. There might also be a little bit of oil that goes into the oil cooler when that opens up as well.

Edit: Also, the 200mL that I added may not be the right amount for you. You'll likely need to experiment, and I would do that a bit more before taking it to a shop. The shop doesn't have any magical diagnostics for you to work with here.

I'll probably do it in 100ml increments because i know how erratic the level sensor can be.

I was suggesting taking it to a shop because very few people seem to experience this problem which makes me think there is something wrong rather than there just not being enough oil in the engine.

[Davisca455]

Top 2 pictures:
In town, just warmed up.

3rd picture:
About 20 minutes down the highway.

4th picture:
Short trip to the grocery store about an hour after getting off the highway.

[pb2707]

Does yours ever drop to the minimum mark? I topped mine up with oil last night and it brought it up to the maximum mark. Going to take it on a run later to see what it does on the highway.

[drrust]

I've had similar issues seemed to get better with resets on the stalk. Especially just after oil changes.

I've also had cases where on several hour drives the add oil warning comes on. After parking for the night the oil is within the operating range. I had a subsequent issue where one of my oil separators cracked and I had to replace it. The long drive issue hasn't come back, but I still get wonky readings just after an oil change.

The other harder to replace item is the PCV valve. The part is not expensive but it is on the back side of the motor and many parts need to be removed to access it.

[Davisca455]

Originally Posted by pb2707

Does yours ever drop to the minimum mark? I topped mine up with oil last night and it brought it up to the maximum mark. Going to take it on a run later to see what it does on the highway.

It did once before, but only after that one time I didn't take the extra time to top it off to the Max level after changing the oil.
I have just over 4000 miles on this oil change (almost all them are on the highway).
Those pictures are the normal behavior for my car.
Right on the Max level in town,
Down to the halfway mark on the highway,
Then back to the Max level again the next morning.

My first oil change after I bought the car, I bought 2 of the 5L jugs and the filter kit.
Drained the old oil, changed the filter, poured in 8.5L, fired it up, let it run for a bit, went thru the iDrive screen to check the oil.
The iDrive screen said "Min" so I added half a litre, checked again, but it was still too low. Kept doing this and finally ended up dumping all 10L before the iDrive said Max.
Take it out for a drive and get the "Overfilled" warning, "CRAP!, a dipstick would be F^[£ing sweet!".
Start pulling oil out of the oil filter housing (multiple attempts) till I finally had it settle on the Max level.
When I was pulling the oil out, I put it in a measuring bowl, so at least I'd know how much to subtract from 10L to get it just right for the next time.
So I always take the extra time to fill the level to Max (like I've been doing with every car I've ever owned), and I haven't had any issues when I get it right.

[pb2707]

Originally Posted by drrust

I've had similar issues seemed to get better with resets on the stalk. Especially just after oil changes.

I've also had cases where on several hour drives the add oil warning comes on. After parking for the night the oil is within the operating range. I had a subsequent issue where one of my oil separators cracked and I had to replace it. The long drive issue hasn't come back, but I still get wonky readings just after an oil change.

The other harder to replace item is the PCV valve. The part is not expensive but it is on the back side of the motor and many parts need to be removed to access it.

What were your symptoms for the cracked oil separator? I’ve just topped up with oil so it reads full. Drove it down the highway for 10 mins and it drops to the minimum level.

I think I’m going to try changing the separators and then if that doesn’t work, change the pcv.

[drrust]

I had pulled my plenum off and it separated at the seam. I would check by trying to wiggle the top section of the separator.

[pb2707]

Originally Posted by drrust

I had pulled my plenum off and it separated at the seam. I would check by trying to wiggle the top section of the separator.

Did you have any symptoms that made you think you had an issue with your oil seperator? Did you have oil on top of your cam covers?

Is replacing them a DIY job or one for a shop to do?

[drrust]

Originally Posted by pb2707

Did you have any symptoms that made you think you had an issue with your oil seperator? Did you have oil on top of your cam covers?

Is replacing them a DIY job or one for a shop to do?

No, as I had mentioned before, had pulled my plenum off and one of the separators had failed at the seam. I still get wonky readings after an oil change.

[akkando]

Originally Posted by pb2707

Did you have any symptoms that made you think you had an issue with your oil seperator? Did you have oil on top of your cam covers?

Is replacing them a DIY job or one for a shop to do?

If you can get the plenum off you can get the oil separators off.

[kyrix1st]

Use the correct oil grade (10w60) and change the oil filler cap. It leaks a lot more from the cap than you think it would. Always clean both sides (valve cover and oil cap) of any oil before putting the cap in.

This is what I would do though, just to be sure.

1. Drain out the engine oil and put 8.8L of 10w60 in it.
2. After the engine oil is warm, press and hold OBC button (left of steering column) so it re-calculates the oil amount in the engine. Sometimes the car shows up the previous value and takes a while to reset by itself but doing it this way, the car is measuring the oil level from ground up.
3. Clean the surfaces of valve cover and oil filler cap.
4. Drive and observe oil level.

[pb2707]

Ok, so the issue keeps happening and i'm now also noticing that my oil level is dropping when i drive it hard. Its not smoking so i'm starting to think its an issue with the pcv system or warped valve covers.

I'm going to replace the valve covers, valve cover gaskets, oil seperators on top of the valve covers and pcv system. If that doesn't sort it, i could be looking at having the engine stripped down...

[RedScytheM3]

Originally Posted by pb2707

Ok, so the issue keeps happening and i'm now also noticing that my oil level is dropping when i drive it hard. Its not smoking so i'm starting to think its an issue with the pcv system or warped valve covers.

I'm going to replace the valve covers, valve cover gaskets, oil seperators on top of the valve covers and pcv system. If that doesn't sort it, i could be looking at having the engine stripped down...

Have you confirmed yet whether there is an actual leak or is it a software issue? If your oil is actually dropping to minimum, where is going? Have you examined the outside of the engine for leaks? Have you tried changing the oil, adding a measured amount of oil to fill, driving until the warning comes on, then draining the oil and measuring how much comes out? It just seems more worth while to really nail down the actual issue before you just start replacing parts randomly. The problem might persist after all that money and work

[pb2707]

Originally Posted by RedScytheM3

Have you confirmed yet whether there is an actual leak or is it a software issue? If your oil is actually dropping to minimum, where is going? Have you examined the outside of the engine for leaks? Have you tried changing the oil, adding a measured amount of oil to fill, driving until the warning comes on, then draining the oil and measuring how much comes out? It just seems more worth while to really nail down the actual issue before you just start replacing parts randomly. The problem might persist after all that money and work

I dont think its a software issue because its had an update and the car isn't throwing any errors or codes. There aren't any visible leaks other than some misting around the valve covers. It seems that at sustained rpm, the oil can't get back to the sump quickly enough which is causing the sensor to throw the warning.

[Mimmer]

I saw this recently on my own car. I don't know the amount but just added more oil. Even though it read full and change later to 3/4 full. After that it was reading full without change 👌. I also read on oil changes to prime the filter with oil as most don't? But Idk if that makes the level changes that much ... just a thought.