75 with oil pressure gauge issues

[My Beast]

gday guys i just picked up 75 series with the 4.2 diesel and it has the denco turbo setup on it what happens is the oil pressure gauge moves when the turbo spools up and when its sitting at traffic lights its saying its got no pressure but it idles perfect while its sitting still and ive checked oil levels and there perfect there dosent seem to be any oil leaks anywere on the motor so im thinking the gauge may have a short so any help with this problem will be much appreciated

[Z()LTAN]

mine has started to do this too mate, i think the senders bugger up on them.

[hillbilliywheelchair]

never trust the factory oil gauge their known to be very wrong go aftermarket

same as the tamp gauge they are dogy from factory to stop people worying

[vk7ybi]

Where does the turbos oil feed come from? I know nothing about turbos and oil, but my guess is that the oil feed for the turbo is taken from somewhere near the oil pressure sensor.. Either the turbo idling reduces oil pressure at the sensor, or the engine/oil pump rotating slower is reducing pressure. The gauge does not have to be calibrated, it is displaying relative pressures in this case..

Another possible cause is that the alternators output voltage is decreasing with lower RPM, and affecting gauges deflection, as the voltage across the gauge is changing.. This might correlate with turbo spool..

Or am I just speculating rubbish?

[My Beast]

thanks guys for that ill check it out today