Oil Pressure low at idle

[Nick H]

Hi I wonder if anyone can help, the oil pressure on my S2 seems low on hot idle. It is showing at 5 bar when cold and 3-4 bar when driving when hot. The idle when hot seems to show about .5 bar! the engine seems to run fine and the warning light has never come on. Any ideas?
Thanks

[mike74]

What type and grade of oil you running? Also when was it last changed? I usually run 10/50 fully synthetic and my idle pressure is never less than 1.8 bar

[RichLV]

1.1-1.3 on 5w40 8100 X-Cess Motul. UrS4 though. Around 3.1 bar at 2000 rpm, oil temp around 80 C.

Use a dedicated oil gauge to confirm. The cluster one isn't the most accurate one.

[mcandmar]

I suspect your pressure sensor is failing, certainly worth changing to verify before doing anything else.

[Nick H]

Thank you for the replies, I am not sure what grade the oil is as I have not changed it since I bought the car. It has 168k but had a top end rebuild at about 130k and apparently new rings etc at 160k but not a bottom end rebuild I don't think. I will look to check the pressure with a mechanical gauge.

[Nick H]

Actually the pressure sensor could be as twice when I have turned the ignition on after a run the warning light and buzzer have sounded, this is just with the ignition turned and not the engine running. If I start it the light goes out and the manual states the light is activated by pressure and not level. Is there only one sensor for the pressure and light and where is it located?
Thanks

[UrS4boy]

Oil Pressure Switch info

Actually the pressure sensor could be as twice when I have turned the ignition on after a run the warning light and buzzer have sounded, this is just with the ignition turned and not the engine running. If I start it the light goes out and the manual states the light is activated by pressure and not level. Is there only one sensor for the pressure and light and where is it located?

The 20VT I-5 engines do NOT have a oil level sensor. That is what ticking hydraulic lifters are for.

As for the oil pressure switches, there are two, F1 and F22, as described here:

http://forums.quattroworld.com/s4s6/msgs/96161.phtml

and here:

http://forums.quattroworld.com/v8/msgs/14490.phtml

[mike74]

IMO, if you're not sure what type of oil is in it then replace it before trying anything else. At least then gives you a better base to start any other trouble shooting. Go for a fully synthetic 10/50 like this one and that should give good pressure at idle, assuming no other issues:

http://www.opieoils.co.uk/p-60235-millers-oils-cfs-10w-50-competition-full-synthetic-engine-oil.aspx

[Error404]

BTDT. Change the "cotton reel" pressure sender

[AndyP]

If you were really only getting 0.5bar at idle, I'm pretty certain your tappets would be clattering like mad. If it sounds normal I suspect a duff reading.

[Nick H]

Thanks for all the replies, I have not yet had a chance to work on the car but will change the oil and replace the sensor. Do you know where I can get the new sensor/sender from?
Cheers
Nick

[Rikki Kitto]

Try TPS

[UrS4boy]

20VT Oil Pressure Sender, Switches, Wiring and Check Valves

Thanks for all the replies, I have not yet had a chance to work on the car but will change the oil and replace the sensor. Do you know where I can get the new sensor/sender from?

From previous discussions that I put in this: http://forums.quattroworld.com/s4s6/msgs/96161.phtml


" UPDATE: I am told by Thuppu on the S2forum that the UrS4 oil pressure sender 034919561 is NLA. This leaves the S2 ABY and RS2 ADU oil pressure sender, 035919561, which is probably identical electrically to the 034919561 (both are listed as 0 to 5 Bar for the sender portion and 0.3 Bar for the secondary pressure switch. However, 035919561 has M10x1 threads. Therefore, to install 035919561 in the M16x1.5 hole, you need an adapter than has the M16x1.5 threads on the block end and the M10x1 on the outer end. This adapter *was* PN 034103179. However, to make things more complicated, I am told that Kate 7.3 says 034103179 has been replaced from December 2008 with Adapter 074103179.

In addition, Thuppu also tells me that the UrS4 1.8 Bar M10x1, white, 1 pin oil pressure switch 056919081E has been replaced in April 2007 with PN 056919081. I have not confirmed this."

Here is a link to the 074103179 adapter: https://www.ecstuning.com/b-genuine-...ter/074103179/



Here is a link to 035919561 info: https://www.ecstuning.com/b-genuine-...der/035919561/

[RichLV]

From previous discussions that I put in this: http://forums.quattroworld.com/s4s6/msgs/96161.phtml


" UPDATE: I am told by Thuppu on the S2forum that the UrS4 oil pressure sender 034919561 is NLA. This leaves the S2 ABY and RS2 ADU oil pressure sender, 035919561, which is probably identical electrically to the 034919561 (both are listed as 0 to 5 Bar for the sender portion and 0.3 Bar for the secondary pressure switch. However, 035919561 has M10x1 threads. Therefore, to install 035919561 in the M16x1.5 hole, you need an adapter than has the M16x1.5 threads on the block end and the M10x1 on the outer end. This adapter *was* PN 034103179. However, to make things more complicated, I am told that Kate 7.3 says 034103179 has been replaced from December 2008 with Adapter 074103179.

In addition, Thuppu also tells me that the UrS4 1.8 Bar M10x1, white, 1 pin oil pressure switch 056919081E has been replaced in April 2007 with PN 056919081. I have not confirmed this."

Here is a link to the 074103179 adapter: https://www.ecstuning.com/b-genuine-...ter/074103179/



Here is a link to 035919561 info: https://www.ecstuning.com/b-genuine-...der/035919561/

Confirming. I replaced mine when was rebuilding the block. Used the adapter (074103179) and an S2/RS2 sensor.

[Nick H]

Thanks, I am a bit confused as my car is an S2 not an S4 so the sender should fit without the adaptor?