Thread: Oil Light Question.

How many ks? How long does the light stay on when you start up?
It is most likely be one of two things.
1 Your engine is completely worn out.
2 The oil pressure switch is worn out.

Either take it to a mechanic to put a mechanical oil pressure gauge on it, or replace the pretty cheap switch and see it that fixes it.

The switch sits on the back of the oil pump with a wire out the top of it. it looks like a little hat .
Regards Philip A

Light stays on for a second or 2 when I start up.
Doesn't come on at all when I just do short trips around town.


Engine is a bit of an unknown, person I bought it off said it has only done 146,000km. Run nice, doesn't leak much oil.

On straight gas.



I will have a look into a new switch, was thinking that might be it cause the oil pressure guage sit around 100kpa when at idle.

Originally Posted by gumby190

I will have a look into a new switch, was thinking that might be it cause the oil pressure guage sit around 100kpa when at idle.

The oil pressure switch does not control the oil pressure gauge, only the light. 100kPa is below normal. Try using a higher viscosity oil, such as Penrite HPRgas, which is 20W-60 and should hold hot idle pressure better.

The Oil Pumps are known for there wearing out.

You either have a chaffing wire down close by the Oil Pressure switch. The higher than normal Engine Vib at Idle might just be enough to cause the chaffing.

Or the Engine has done much more than 150 KM. The oil pumps do have a habit of not providing enough pressure at idle, but only after 300, 000 Km or so.
Could also be the Pressure switch takes a higher pressure to extinguish than normal to operate.

The Eliminate any wiring or Binacle problems disconnect the wire from the pressure switch when the vehicle starts playing up. Disconnecting the wire will simulate normal oil pressure with no light on. Obviously if the light is still flickering on then its electrical chaffing or binacle problem. If not then you need to be looking at the switch or Oil Pump.

Hope this helps.

I had a flickering oil pressure light so I fitted a new switch, problem solved. Although I did fit a gauge, just to be sure. The cheapest & easiest thing to check first. The price varies from $50 at Ritters to $6.99 for the same part no.(see link below).
Hope this helps.
Adam.

OIL PRESSURE SWITCH RANGE ROVER UP TO 1986 | eBay

I'm with Philip. I would be inclined to have someone (mechanic) put a gauge on it to be sure. Low oil pressure is not so much a sign of a worn-out oil pump as a worn-out engine; as bearings wear, the clearances increase and the oil flows freely past the bearings and into the sump.

Changed the oil pressure switch, the little light is not flickering now.

Changed the oil & filter while I was at it.




Thanks for your help/advice.

The varying conditions - engine temp/rev and intensity of light suggests that its worn wiring; seems most logical to me. My brilliant Rover mechanic disagreed and said not to bother with a/mkt gauges as the sender at block works fine, is cheap enough to replace and will likely fix the prob. Its a 91 RRC 3.9 EFI done only 88000k, uses no oil and thats what I'll try first. Though I would still feel better with a decent mechanical guage rather than relying on the Lord of Darkness for my oil pressure reading!