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New S2 Avant Nothelle N300 owner

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  • I am experienced enough in unusual / unexpected oil warning lights on my auto check to comment... Check the part number of the cotton reel type sensor you have fitted. The ones audi use in these engines is different to the ones vw use in the golf family engine despite looking identical.

    I have fallen foul of bargain hunting and fitted a brand new vdo oil gauge sender unit from vw heritage as unaware of any differences; it was significantly cheaper than audi. The internal switching contacts for pressure warning operate differently for vw and mine constantly triggered the beeping at 3000rpm.

    If you have only just ventured there in your run in routine that my explain why you have only just experienced it.

    Check the numbers or if unable to see any I would try a good second hand unit that can be verified as coming from a 5 cylinder engine.

    You live and learn.

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    • Thanks Steve.
      I haven't bought a new one yet as I did read about compatible issues. I'm still in the original one. I did try a second hand original but that caused the auto check low oil pressure buzzer. Someone is sending me another
      Nothelle S2 Avant in restoration

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      • I can't remember from your thread if you ever had the engine running on collecting the vehicle. Its not beyond possibility that it had an incorrect one in there when you picked it up...
        After rebuilding my engine 3 years ago and getting many many new bits for it including the cotton reel type vdo sender, I felt sick when I started getting oil warnings. The problem only manifested itself once I got confident enough to open it up a bit and then it stayed beeping and flashing!

        Have a read through this lot and see if this sounds familiar to what you are getting...

        https://www.s2forum.com/forum/techni...and-what-to-do

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        • Just looking at some available VDO senders and it does seem that they operate in the 10-184 Ohms range 0-5bar. The tolerence is large especially at the higher pressures where anything from 154 - 214 ohms is a 5 bar reading. In fact the bottom 5 bar tolerence is within the mid to high range tolerence of 151-162 Ohms for the 4 bar measurement.
          So its true they are not a particularly accurate way of measurement but its a bit alarming to have a gauge pegged at max all the time!
          Last edited by twoqu; 29th July 2019, 13:26.

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          • I bought a new toy

            Just over 5 bar at start up

            Dropped to about 3 when the oil was warm.
            I tried another sender (used). I had the same problem as the last one I tried. The auto check said low oil pressure and on starting the engine gauge went straight to max and stayed there.
            Really scratching my head now. Must be something still up with the wiring I think.


            Sent from my iPhone using Tapatalk
            Nothelle S2 Avant in restoration

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            • I set up an external battery with a buzzer and tested each wire. I had a good buzz from the black and white sender wire. But also had a feint buzz from another wire at the plug...... so I have a short!
              It was a real PITA but I removed the loom.
              I’ve stripped the insulation and there is no sign of a short. It must be very minor. Some of the wires were joined together by the heat and the insulation must be compromised. I will replace all the wires that look damaged.



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              Nothelle S2 Avant in restoration

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              • Sounds promising! Tenacity has hopefully paid off

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                • Replace every wire Dave.
                  Panthero Coupé quattro 20vt
                  Indigo ABY coupé
                  Imola B6 S4 Avant

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                  • Originally posted by Error404 View Post
                    Replace every wire Dave.
                    Are you still busy?
                    Nothelle S2 Avant in restoration

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                    • Always
                      Panthero Coupé quattro 20vt
                      Indigo ABY coupé
                      Imola B6 S4 Avant

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                      • As Error was busy I decided to have a go myself.
                        I got some wire

                        And some high temp sleeves.
                        Every wire that showed any sign of heat damage was replaced and individually sleeved. Tessa high temp tape then used to wrap it all up. All lines tested and good. Nil shorts.

                        Put it all back in the car.
                        And......hey presto, same fault as before ☹️


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                        Nothelle S2 Avant in restoration

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                        • If you know which pin in the circular connector is back to the gauge you could try something along the lines of the following.
                          First find a relay from your collection and see if you can get a relatively low reading from across the 85 and 86 terminals. For example I have a 217 relay that has a resistance of 52 ohms. Then connect a wire to earth from one terminal and feed the other into the gauge pin. In effect thats simulating a low pressure signal which should move the gauge down the scale. If that works then at least you know everythings ok back to the guage from the connector. If it still does not work then it points to wiring back to the guage or the gauge itself. You only need the ign on to do this.
                          I sort of used this technique to troubleshoot a coolant gauge which didn't want to budge. Turned out the wire in the gauge was broken! Sort of the opposite to your problem but maybe helpful. Other than that I would measure the front and rear of that circular pin in case there is a high resistance in the connector.
                          Do the other gauges make sense?
                          Last edited by twoqu; 7th August 2019, 19:58.

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                          • Thanks very much twoqu, that's very useful. If I take a reading from the gauge itself and see what's happening there, I'm looking for resistance change rather than a voltage change?
                            Nothelle S2 Avant in restoration

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                            • Well we know it takes a certain amount of resistance to peg the gauge above say 200 Ohms as thats what the sender does.
                              If we can feed in a known resistance lower than that the gauge should move down the scale. Something around 50 Ohms should be about 1 bar, 10-15 Ohms should be 0 bar. All we are doing is taking away the variability of the sender.

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                              • Thinking about it you already must have something that reads a low resistance in the form of the sender that reads 10 Ohms! Hook that up as above making sure you have a good ground. If that does not move the gauge then they must be a break in the wire from the connector back to the gauge or its not connected. Its the variance in the current that moves the gauge.

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