# Oil level sensor problem - calling all gurus.



## silkman (Jul 29, 2004)

My oil level sensor hasnt worked a few years now frustrating me because I would have to check oil manually. Some times the TT wouldn't use a drop of oil and some others it would eat up a liter of oil in less than a month.

History maybe in the last 3-4 years. I had changed the oil sensor with an aftermarket JP part (didnt work) and asked them for another part which didn't work as well when installed. Left it there because to change the oil sensor you need to either have it booked for a scheduled oil service, or throw away oil and refil. Not to mention its not a diy job because you need to lift the car up and remove and refit scuttle panel etc.

Lastly I had bought a hella part which apparently is exactly the part sold by Audi (with the Audi logo ground off) so lets say that is OEM, which was installed at the last oil change. Thought I was done with the problem.
Hella part 6PR 008.079-941









And then this happened on Saturday.









Called my mechanic who advised me first to put a paperclip in the engine lock socket so that we rule out the engine lock as a failure point. 








Without adding oil, I started engine maybe 5-6 times with the paperclip on and off, no low oil indication on the dash.

Yesterday I went to the garage and spent considerable time with no luck: 
-First we drained 2 liters of oil which would have been enough for the indication to light up.
-Checked dashpod module in vcds with no errors and the sensor would read oil temperature ok
-Checked the 3pin sensor plug coming from the car: pin 1 is +12v with engine on (ok), pin 2 is ground (we had a good ground) and pin3 goes to the dashpod: We even took the dashpod out and checked that theres connection with the sensor pin3 wire which goes to pin 15 of the green socket in the dashpod (connection was good)
-If we removed the socket from the oil sensor, we would immediately get the yellow "OIL SENSOR" indication on the dashpod.

But no low oil level :?

Edit: Audi Parts for oil sensor are
1J0907660B up to 2002 cars (mine is a 2001)
1J0907660C from 2002 cars onwards

Thoughts? [smiley=bigcry.gif]


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## Spliffy (May 3, 2013)

So it's probably a wiring issue , but why are you relying on the sensor and not just manually checking the level weekly, assuming you use it daily ?
Nick


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## silkman (Jul 29, 2004)

Spliffy said:


> So it's probably a wiring issue , but why are you relying on the sensor and not just manually checking the level weekly, assuming you use it daily ?
> Nick


I think by taking the dashpod out we conclusively proved it is not a wiring issue. All 3 wires going to the sensor are good.


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## Delta4 (Jun 19, 2015)

Thoughts  checking the oil yourself tut tut you don't wanna do that it's labour intensive :lol:


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## silkman (Jul 29, 2004)

Delta4 said:


> Thoughts  checking the oil yourself tut tut you don't wanna do that it's labour intensive :lol:


Thats what I've been doing all this time :wink:

OCD MODE ON: The bloody sensor is there, I paid money for it, it should work. :roll:


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## Hoggy (May 8, 2002)

Hi, Nice to have it working, but I would never let my oil get halfway let alone anywhere near minimum.
Quite a complex system, nothing simple on the TT.
Hoggy.


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## Hoggy (May 8, 2002)

Hi, Check fuse No. 5, 11. & 15
Hoggy.


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## StuartDB (Feb 10, 2018)

didn't silkman say when the cable is disconnected from the sensor the yellow alarm comes on; surely it is either a sensor or an oil level fault, but why on earth would you want to rely on an alarm to tell you it is empty of oil? you will need to stop the car and walk to a station. 
A lorry and tractor driver and even a company car owner is expected to check tyres, oil and water before they even start their vehicle (it is part of an inspection to ensure it is road worthy before going on a public highway) and you want to be told when there is no oil left? I haven't had the alarm show up when the oil is not even on the dipstick after an issue with my S3.


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## Hoggy (May 8, 2002)

StuartDB said:


> didn't silkman say when the cable is disconnected from the sensor the yellow alarm comes on; surely it is either a sensor or an oil level fault,


Hi, Lets wait until silkman has checked the fuses. :roll: 
Hoggy.


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## silkman (Jul 29, 2004)

Hoggy said:


> Hi, Check fuse No. 5, 11. & 15
> Hoggy.


Hi Hoggy. Checked all fuses actually with a continuity voltmeter. The big ones in place, and removed all the small ones and checked them. All OK.

Played a bit with VCDS. Oil temp is through the oil level sensor and confirmed working as below while the car warmed up. However I couldn't find an indication on the VCDS for oil level (engine and instruments modules). Can someone confirm with VCDS? Maybe my instruments are coded wrongly when Audi replaced them (on some older Golfs you can enable/disable oil level display warning)?

Oil temp rising in engine warmup. 

















No oil level in "instruments" or "engine" module in VCDS. Shouldn't there be one? Only found an "oil quality" reading.


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## StuartDB (Feb 10, 2018)

pretty sure the oil level sensor doesn't know the level - it just alerts when there is none. a bit like the oil pressure sensor or coolant level sensor - it is binary 1/0 on/off alert/quiet buzz/shush yes/no


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## Hoggy (May 8, 2002)

StuartDB said:


> pretty sure the oil level sensor doesn't know the level - it just alerts when there is none. a bit like the oil pressure sensor or coolant level sensor - it is binary 1/0 on/off alert/quiet buzz/shush yes/no


Hi, It's a bit more complicated than that, it uses oil temp, time & all sorts of things. Nothing simple on a TT.
Hoggy.


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## silkman (Jul 29, 2004)

StuartDB said:


> pretty sure the oil level sensor doesn't know the level - it just alerts when there is none. a bit like the oil pressure sensor or coolant level sensor - it is binary 1/0 on/off alert/quiet buzz/shush yes/no


Still shouldn't be there a binary field in vcds?


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## Hoggy (May 8, 2002)

silkman said:


> StuartDB said:
> 
> 
> > pretty sure the oil level sensor doesn't know the level - it just alerts when there is none. a bit like the oil pressure sensor or coolant level sensor - it is binary 1/0 on/off alert/quiet buzz/shush yes/no
> ...


Hi, F*** the binary check the fuses. [smiley=furious3.gif] 
Hoggy.


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## silkman (Jul 29, 2004)

Told you I checked them all. All fuses are OK.


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## StuartDB (Feb 10, 2018)

Hoggy said:


> StuartDB said:
> 
> 
> > pretty sure the oil level sensor doesn't know the level - it just alerts when there is none. a bit like the oil pressure sensor or coolant level sensor - it is binary 1/0 on/off alert/quiet buzz/shush yes/no
> ...


oh.. thats interesting; so essentially even though there's a post in the sensor it's not just on/off like a brake sensor, coolant sensor etc, it needs to guess how much oil is travelling around the engine based on RPM (oil pressure), engine temp (viscosity?).

The problem with giving too much info to the driver; like oil pressure, absolute oil level, pump efficiency, filter efficiency etc etc is we are paranoid so will look for problems. you would have thought they could not allow the engine to be started and put up a message "Hey dude I dont think there is enough oil in the car - I am cold (coolant sensor) and on a flat surface (head light levelling)" are you sure you wanna start me?"

_DONT LAUGH --- out of interest do electric cars have any oil - maybe for battery cooling, or some form of gearing_


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## Hoggy (May 8, 2002)

Hi, Most cars in my experience have an oil pressure alarm until engine running, but not the TT.
Nothing simple on a TT. :roll: 
Hoggy.


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## darylw357 (May 21, 2019)

How is the bonet switch related to the oil level sensor?


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## Hoggy (May 8, 2002)

darylw357 said:


> How is the bonet switch related to the oil level sensor?


Hi, If you have a low oil level alarm, you have to lift the bonnet before alarm will clear.
Common sense means you would check the oil level before continuing.
Vorsprung durch Technik which makes sense for a change  
Hoggy.


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## StuartDB (Feb 10, 2018)

he he - so this is TT oil warning 2.0?

"Hey dude I dont think there is enough oil in the car - I am cold (coolant sensor) and on a flat surface (head light levelling)" are you sure you wanna start me?"


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## silkman (Jul 29, 2004)

Any more ideas regarding the topic at hand? I would tend to think that dashpod needs to be checked but how?


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## Hoggy (May 8, 2002)

silkman said:


> Any more ideas regarding the topic at hand? I would tend to think that dashpod needs to be checked but how?


Hi, Surprised it wasn't a fuse. Same probs & tests carried on the Golf forum & in the end it was fuse 15.
The 3 fuses I mentioned for TT are to do with instrument cluster. More searching req.
Hoggy.


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## silkman (Jul 29, 2004)

Next up dashpod, the obvious culprit. Need to take it out, replace the DIS screen since I'll open it up and inspect for cold solder joints.


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## LesRSV (Jul 5, 2017)

silkman said:


> Maybe my instruments are coded wrongly


Can you not check the coding and see if the level sensor is active.In the coding, some modules will list other options depending on what you want to enable/disable.Might be worth a look.
I would be concerned about why it's losing so much oil.Anyway,hope you get it sorted.


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## silkman (Jul 29, 2004)

LesRSV said:


> silkman said:
> 
> 
> > Maybe my instruments are coded wrongly
> ...


Did check coding and there's nothing in the likes of "enable oil sensor". I will check some more.

Your thoughts about oil loss are relevant. At the garage we still saw some oil at the top of the undertray but can't find where it comes from yet. Cam halfmoon seal has been replaced a year ago which leaked substantially.


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## LesRSV (Jul 5, 2017)

silkman said:


> Did check coding and there's nothing in the likes of "enable oil sensor". I will check some more.


I can't remember if it's in long coding or adaption,but when the current coding is displayed there is a drop down menu for the various options,but perhaps is not relevant for level sensor?
Apologies if I am trying to teach granny how to suck eggs. :lol:


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## silkman (Jul 29, 2004)

LesRSV said:


> silkman said:
> 
> 
> > Did check coding and there's nothing in the likes of "enable oil sensor". I will check some more.
> ...


Nothing on the drop down, I remember that. Only "oil quality" setting which is longlife or standard service intervals.


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## A_Banging_Donk (Apr 22, 2017)

Oil level warning fires beyond the end of the dipstick, I've had it once on the TT and a few times on the A4, dipstick always came out dry.

Yes your oil is low in the pic but nothing to worry about.. just chuck a litre in and get in the habit of checking it every tank


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## JoeKan (Mar 10, 2019)

FYI on how the Oil Level sensor is documented - from the "Audi TT Coupe - Study Guide"

































Could be that the Oil Level Sensor is not firing due to a faulty resistor or other electronic 'issues' within the sensor unit, even 'dirty' electrical connections.


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## StuartDB (Feb 10, 2018)

I think sensor fault has been ruled out after 3 sensors exhibit same behaviour.

_So in a pre oil level sensor TTs, service intervals were purely distance related_


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## silkman (Jul 29, 2004)

Great info there JoeKan.

As it's stated, the oil level is inferred from the oil temperature and the oil sensor only measures oil temperature. That's also consistent with the fact that theres no "oil level" field in VCDS. And in my case we have proven that oil temp is measured correctly. Which brings us to the next possible culprit.

Dashpod.

And, despite that oil wasn't past the lowest dipstick level when I first saw it (photo in OP), at the garage we removed 2 liters of oil which should be plenty to make the sensor light up. But we didn't leave the engine on enough like 10 minutes to see if the low level would come up since its a question of the sensor element cycling heating and cooling. As there wasn't enough oil, we checked with the engine on briefly (like maybe 30 seconds) which maybe wasn't enough.

So next oil change I will add only 2 lit of oil and let the engine on for 10 minutes for a conclusive result...


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## JoeKan (Mar 10, 2019)

I seem to remember the old adage about the oil level light - If it comes on, it's probably too late for the engine as it has possibly been already damaged by running it with too little oil. Although... I can't see Audi doing that intentionally, it may be a by-product of their 'innovation'.

Silkman - while a tempting thought to prove a theory... I wouldn't take that chance at damaging or adding excessive wear on your engine. My 2 cents of wisdom. I don't know what the bare minimum of oil for that engine might be.

I've had the light go "on" in my previous cars when I was younger - usually a result of not checking whether the spin-on oil filter rubber gasket is still in the old filter after I removed it. The old gasket was stuck to the underside of the filter mount. 
After installing a new filter, there were now 2 gaskets rather than one, and the oil would blow out somewhere during the 1st trip. The only way I knew was when the oil light came on after the engine blew out most of the oil. Immediate reaction was to turn the ignition OFF, coast to a stop and investigate.

"DUH!!" moment - twice. I learned.


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## silkman (Jul 29, 2004)

Joe you are correct, noone should rely on the oil level sensor because by then it may be too late. Always check the dipstick regularly.

However, its an extra level of protection, in case our cars develop a sudden oil leak.


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## wolff1 (Jul 25, 2010)

Hi fellas, the minimum level light comes on the display. I’ve changed the oil and it’s on the maximum. But when I lift the oil dipstick and put it back in, the light goes out for two- three days? Any ideas? TT 1.8 quattro


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## gedu (Sep 2, 2021)

broken sensor, pulling dipstip cancels the message from sensor for some start amount. Or rather it's the opening of hood that does that.


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## Hoggy (May 8, 2002)

wolff1 said:


> Hi fellas, the minimum level light comes on the display. I’ve changed the oil and it’s on the maximum. But when I lift the oil dipstick and put it back in, the light goes out for two- three days? Any ideas? TT 1.8 quattro


Hi, Remove the connector on the sensor, clean up & replace, Hopefully just a poor connection.
Hoggy.


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## wolff1 (Jul 25, 2010)

Thanks for the answers fellas. I actually changed the censor a few months but most likely it’s broken again. Btw if I want to clean connector, I should do it with a contract spray or something I wonder?
I’ll try to clean it and see if it works out and if not, then replace it


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## Hoggy (May 8, 2002)

wolff1 said:


> Thanks for the answers fellas. I actually changed the censor a few months but most likely it’s broken again. Btw if I want to clean connector, I should do it with a contract spray or something I wonder?
> I’ll try to clean it and see if it works out and if not, then replace it


Hi, Yes & make sure the connectors are clean & shiny. Been through any deep water recently?
Hoggy


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## wolff1 (Jul 25, 2010)

No deep water but it was in a few months back. Maybe that is


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## davebowk (Aug 16, 2019)

Get some ACF50, it will eat away corrosion on connections and prevent further problems


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## wolff1 (Jul 25, 2010)

Thanks for the advice Dave


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## wolff1 (Jul 25, 2010)

gedu said:


> broken sensor, pulling dipstip cancels the message from sensor for some start amount. Or rather it's the opening of hood that does that.


Exactly that seems to be the problem. I cleaned the connectors of the censor and it’s still making the problem. I’ll replace the censor soon and hopefully It’ll solve it 

when I open the hood, the light goes out for a couple of days


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## silkman (Jul 29, 2004)

wolff1 said:


> Exactly that seems to be the problem. I cleaned the connectors of the censor and it’s still making the problem. I’ll replace the censor soon and hopefully It’ll solve it
> 
> when I open the hood, the light goes out for a couple of days


If you replace it, get only a Hella part, or one from Audi (which is exactly the same, made by Hella). Every other aftermarket part is crap and won't work. I've replaced 3 or 4 sensors and the last Hella part has been working fine for a few years now.

Are you sure the message you get on the dash is yellow low oil warning, or does it say yellow low oil with sensor below it? The latter means its a problem with the sensor..


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