Oil Sensor Fault?

A6 All/ S6 All
#1

Hello,

Has anyone ever had a failure of the oil level sensor?

I had a check oil fault 3 times on a recent 250KM drive back at high speeds. The first time, I checked the level and it was just as the MIN on the dipstick. Added 400 ml of oil. The second time it was again at the MIN level on the dipstick, added 600 ml of oil. The 3rd time it was also at MIN on the dipstick, and then I realized I should wait a moment for the oil in the engine to settle down. After 5 mins, I checked and the level rose to just above the scratched line on the dipstick. So I did not add any oil. The fault stayed on, but after I 30 mins when I was driving slower in an extended construction zone, it went off.

When I returned home, the oil level was the same, just above the scratched line. This is where it has been for the most part since I last changed the oil, 3700 miles ago.

Thoughts?

#2

When I’ve had the low oil light come on, I’ve had it come back on a couple days after adding a quart of oil. In my car, I’ve found that by the time the low oil light comes on, it really needs about 2 quarts by that point. There was a time I thought my sensor was bad too, but really the car just WAS that thirsty for oil. Keep in mind that many of us burn about a quart of oil every 1000-1500 miles, which seems about standard for higher-mile VAG cars.

#3

These cars take almost 11qts of oil, so I’m not really sure how many quarts missing is considered “dangerously low”. Apparently audi thinks the answer is somewhere between 1-2 quarts.

Also, when you get an oil change, there’s a good chance they only put in 10qts, which means you’re already over 1/2 a quart light from the get go.

#4

I can buy that argument, the car used to require 250ml every 1000KM. But then I had all the key engine gaskets changed and it seemed to have been steady ever since.

What is the best practice for checking engine oil levels? I swear that the levels increase a few minutes after the engine is switched off. But it’s most convenient to check levels right when you pull into the gas station.

#5

I had the sensor go off last night. I scrambled to an auto store to get oil just in case. Came back outside, restarted the car to double check first, and it hasn’t come back on since knock on wood. I have the bottles in the car just in case but I guess I need to find a permanent way to store one in the car now

#6

My experience exactly. I’ve had the oil sensor go off when driving up a mountain on cobblestone roads (very bumpy). I added oil at the peak and then discovered a couple days later that I was now overfilled.

Later, when I had the intake off I discovered it was full of oil—and my oil separator membrane was torn. But the oil separator was replaced a long time ago. I’m still not sure where the oil goes when I’m driving for long distances on rough roads.

#7

Yeah thank goodness I randomly thought to check first. I know they make a big deal out of not overflowing these cars. Maybe JimmyBones or CV or one of the other guys can chime in with more technical insight.

#8

Correct, when the light comes on check. The oil, don’t always add. The sensor is sensitive, additionally if you are driving hard or conditions vary widely especially on a long or very short road trip, you can trip the oil sensor. Happened to me three or four times over two and a half years on my last s6. Same thing happens in my Cayenne GTS. No biggie, just monitor and within acceptable range do not fill, if lower than acceptable range or dip stick is completely dry add a little :wink:

Defer to Jimmy on a more official answer but thats my experience.

#9

Always check the level before adding. I have had to replace a bunch of oil level sensors on a bunch of different Audis because they would randomly say that the oil level was low when it wasn’t and the warning light finally got annoying enough to the person that they were willing to spend the money. On my personal cars whenever the warning for low oil level comes up then it is low from between a quart to two quarts depending on the car and situation.

Also I pulled my intake manifold off after driving on my trip last year and when I went to pick it back up to reinstall I noticed that like two quarts of oil was leaking out of it. The oil pooled on the bottom of the intake manifold and just sat there until the manifold was tilted enough to leak out. Don’t be surprised there.

#10

Update. My car said I had low oil again 2 night ago. Cut car off for the night when I got home. Next morning, cut car back on, warning light was still there. Cut on/off 3 more times to make sure… warning light still there. Added about 1/5-1/4th quart. Cut back on, warning light gone… Oil change time was coming up within the next 700 miles or so, so I went ahead and got an oil change yesterday anyway. Mechanic said that oil level was actually a little low this time, but no leaks, etc. They went through the effort of checking the level after the change, before and after running the car for a bit, so it’s at the max now. Not sure if any of that information helps, but just FYI for logging.

#11

That was a much better technical response. Thanks Jimmy. These sensors and cars can be quirky as wel all know. I appreciate the quirkiness at times, but if you don’t know about this stuff it can be fairly annoying.

#12

Taking my car in on Friday for an oil change and replace oil level sensor which has been annoying me for a month or two. I would normally do this stuff myself but have heard good things about a local foreign indy and got quoted $30 for filter,$87.50 for Liquimoly 5w40 and $120.00 for sensor. Labour is $99.00 total. All prices in $Can. Will post again after some seat time.

#13

Fair pricing, especially if they do good work :slight_smile: let us know how it goes, fingers crossed that this alleviates the annoyance so you can get back to happy v10 motoring.