oil pressure gauge oddness

[bernsaudi]

ello all!!
I have just fitted an aan engine into my car, and the oil pressure on my car has become odd......

upon first starting the oil pressure gauge went off the scale, so we swapped the wires. now the gauge reads 0 until starting, then goes off the scale and stays there until i turn the engine off. the sensor is in a different postition to the aby and it is a git to get at now. any ideas?
Ta!

[Fat Audi 80]

The pressure guage should go off the scale when starting. It will settle to around 1.5 - 2 bar once the engine is warm. It sounds like you were right first time.

As a test it should read at least 2 bar at 2k rpms when warm, and shoot up to 4.5 bar at you increase revs...

[bernsaudi]

the gauge went off the scale on first fitting with only the ignition on, not engine running.
upon wire swap the gauge stay at over 6 bar but starts at 0 when the ignition is on. it is the same sender and loom and ecu as my aby. I am aware of the running figures and this is defo electrical. anyone had this happen?

[Error404]

sounds normal, you had the wires the wrong way first.
the aux gauages aren't very accurate, what you posted sounds fine to me. As Steve suggests let it warm up and see where it reads when up to temp
(1.8 - 2.2bar is about right)

[bernsaudi]

it stays off the scale when warmed up, that is what is doing my head in!!!panic!!!
havent got a smiley for panic!!

[bernsaudi]

decided to stall the car today to see what happens to the gauge, as soon as it stalls it goes to zero.....but during any other time it is buried over the 5 bar mark, even after an hour or so...

[FeaRThiS]

Mine only ever drops to 3 bar even after driving for 3+ hours

[bernsaudi]

i swapped ecus and that didnt change things either, whether the gauge is part of the sensor I don't know.
Its a bit unnerving cuz i just changed the engine and I cant keep an eye on it..just watching oil temp instead.

[Rusty]

I had this today when playing with the gauges. I realised that I'd left the brown, second plug unplugged - plugged this back in and all was OK. Hope this helps. I can only guess that this plug is required to ground the gauges.

[bernsaudi]

I heard ya, I'll have a look....

[Rusty]

Cool, hope it solves the issue...

[bernsaudi]

whereabouts is the brown plug...? Havent opened my eyes yet...!

[Rusty]

comes off the gauge wiring loom.

[sam80quattro]

i seen this happen a while ago when a mate used mole grips on the body of the sender to remove it when swapping an engine and it crushed it and always read dead high..... how did you swap the sender

[bernsaudi]

...cant answer that one, it was my heavy handed mate...so.... :mischeif: