Oil level sensor

[Explod]

Hi, I am a newbie from NZ and my first issue (and only thus far) with my 2004 3.0 Z4 is the oil level sensor. The yellow light came up on after a warm start up within 20 seconds and diligently deleted itself after 12 or so seconds. I then diligently bought a German made sensor, not a Hella admittedly, but it is a good German one. I removed the old sensor placed it with the new and alas the yellow light still shows as above for 12 seconds and then goes. This ONLY happens on a warms start up ...never from cold.

I took it to a very professional car electric shop and they could not clear the yellow light after scanning the car. The code that came up on their scanner was ‘27C3 thermal oil level sensor’. Alas I had replaced the aluminium tray at this point so the connection could not be probed with a volt meter by the shop. I intend to remove the tray and take it back to the electric chap next week. In the mean time has anyone got any ideas on what this could be?

I saw one chap stripped down his connector to the sensor (after having replaced 2 sensors) and found one of the 3 wires to the rear of the connector had broken, how that happened I have no idea as the connector is so, so well protected by that impenetrable aluminium tray.

Anyways, there you are. My little saga. I know it is not a biggie as it is only about the oil level sensor (and not oil pressure, that’s the red oil icon) and after all we can check our dip sticks at will, I would just like to get to the bottom of it and get it working as it should. Any help on this matter would be greatly appreciated. I thank you all.

Dominic.

 

[Mr Tidy]

Hi and welcome to the forum Dominic.

Sorry I can't help with your issue, but just be grateful your Z4 has a dip-stick - my first two Z4s didn't and relied on the sensor! :roll:

And you may want to make yourself known on this thread:- https://z4-forum.com/forum/viewtopic.php?f=11&t=126158&start=15

Anyway we do like to see photos of new members' cars on here so if you are quick you might be able to avoid a visit from the photo police!

 

[Chris_D]

My oil level sensor hasnt worked for the last 2 years.
Have a replacement to go in but as i suck out the oil rather than drain i havent had the opportunity or inclination to replace the sensor.
Check level every week/ long drive and its fine.

 

[Explod]

Thank you for the information, it really does seem like there is little point in cars having an electric oil level sensor when you have a manual dipstick!! Of course I see the relevance like in my daughter’s 120i where there is no dipstick an oil sensor is obviously essential, otherwise you cannot know your oil level.

 

[Explod]

Turns out the replacement oil level sensor I fitted was defective. Simply fitted a second, better quality one and the issue has gone away. Nice to have no warning lights!

 

[Chris_D]

You drained (and wasted?) your oil just to find the replacement sensor was faulty? :?
I presume then you fitted a third working one after clearing the code and then re-filled with fresh oil?
If so, well at least your engine got an expensive flush.

 

[Roberltd2]

Could be worth a read:
https://www.e90post.com/forums/showthread.php?t=1533444

 

[Conrod]

That's a very useful link, even for M54 engines.

I'd often wondered how engine oil quality was monitored, and now I know. I can also now see why it takes so long for oil sensors to determine the level, and that makes it all the more puzzling as to why the sensor was considered to have made the reliable, instant reading mechanical dipstick redundant on later engines!