Faulty Electronic Oil Level?

[jamie297]

Hi all - First time posting in the forums as only had my 2007 2.0 Z4 for 2 weeks. Seems like a decent resource of info here, so was looking for some help.

Car was serviced just before I bought it, and 13k until the next oil service. But a few minutes into driving to work today the oil warning lamp lit up yellow showing zero bars and the "+1.0" so I thought I'll get some oil on the way home.

After work the light didn't appear. On the way to Halfords I was stuck in traffic so tested it and it went from zero bars up to 1 bar, and then the yellow light came on again, which I thought was fair enough as was similar reading (give or take 1 bar).

After buying the oil and in Halfords car park I thought I'd test once more before filling up, and to my surprise it showed "5 bars OK"!! On the motorway on the way home (again warning light not on) I thought I'd test it while cruising along at 70mph and it showed full 5 bars and the "OK" message.

Back in town, nearly home stuck in traffic I tested again and it went back to 1 bar, yellow warning light and "+1.0".

The manual says that if the "warning lamp lights up in yellow within 30 seconds after the engine is started: the oil level sensor is defective.", so by that indication the sensor isn't faulty?

Any advice much appreciated, I'm reluctant to fill with oil if it is in fact "5 bars OK"...

 

[srhutch]

I had this once or twice on my old car so knew to ignore it. Keep an eye on it, but unless you know it has dropped you don't want to be adding another litre.

If you check it weekly, which is easy driving along then you will see it drop gradually and know when it does need topping up.

 

[skelters]

Have you checked to see if there is an oil leak anywhere?

Just in case there is a bigger issue.

 

[Scooba_Steve]

When I first got mine I had an indy do the inspection 2. A week or so later, parking on a hill at work, I found I started getting oil warnings.

Long and short of it was they hadn't filled it enough. If I were you I would be taking it back and asking them to drain and fill, measuring what comes out and watching them do it. Worth taking pics of the warnings when they come up. If it happens after that start looking at the sensor, then other issues. Put all of this back on them and get them to fix it.

 

[jamie297]

Thanks for the replies! Update is I've just been to pick my GF up from work and when I arrived I did an oil test and it said empty "+1.0" and then the warning light came on...

Then on the way home the yellow engine warning lamp came on too!

To be safe I've put 0.5 ltr in then will check tomorrow when I get to work. Hopefully it will have gone up to 2-3 bars. If it does then I will top it up to full...

 

[Fastatv]

Something similar has happened to me, though my car is a 3.0I, and a 2004 model. By the way, I change my own oil and filter which is an easy job except for trying to get a jack under the car. Anyway, when I had changed and gauged my oil, it showed full on the dipstick when it was actually about 1/2 quart low. I found that I was gauging it incorrectly. When I checked the oil with engine totally cold, it always read full. Then I read the owners manual and it indicated the process below. By following this process, it was in fact 1/2 quart low. I added the 1/2 quart of oil and the "light" has not been on since.
Checking the oil level
1. Park the vehicle on a level surface
2. Switch the engine off after it has
reached normal operating temperature
3. After approx. 5 minutes, pull the dipstick
out and wipe it off with a clean lintfree
cloth, paper towel, or similar material
4. Carefully push the dipstick all the way
into the guide tube and pull it out again
5. The oil level should be between the two
marks on the dipstick
6. Return the dipstick to the guide tube,
inserting it as far as it will go.
As with fuel economy, oil consumption is
directly influenced by your driving style and
vehicle operating conditions.

 

[jamie297]

Hi mate - thanks for the reply but my 2007 doesn't have a dipstick, it only has the electronic "5 bar" oil level on the display... I can understand some arguments for this, but personally I don't think such critical test equipment should be purely reliant on electronics/sensor.

That's why I had to query if it was in fact faulty, I was getting contradicting empty/full readings. But like you said, I think my 5 bar/OK readings were false as I was checking whilst the engine hadn't reached full operating temperature.

Fortunately the 0.5ltr I added last night has taken it up to 4 bars which I'm happy about. Means the empty readings were correct and explains for the engine management lights coming on. I haven't had any sorts of warnings since topping it up last night and now consistently reads 4/5.

Just need to bear in mind that the check is to always be done 10-15 minutes into a drive whilst on a flat surface.

Thanks for your suggestions.