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View Full Version : Oil pressure warning light coming on at idle.



SuperRover
22nd April 2009, 07:52 PM
Hi, I have a series 2 disco running the 4.0 V8 (done around 118,000km) and I just noticed tonight that the oil warning light is coming on at idle and disappearing once I apply some revs.

So to be specific, once the revs drop below 750rpm the light appears and idle tends to be just under that (is idle too low perhaps?). I'm assuming my oil pump is on it's way out, but I've only had the car for about 6 months so still learning the ins and outs.

I did an oil change last week and the level is still on full despite the customary leaks, but I did find the new oil filter was slightly shorter than the one I removed, so maybe this is playing a part?

Can anyone tell me what is involved in replacing the oil pump, time cost etc. because I might start with that and hope it fixes the (bitch) fault. Or if anyone has an idea as to what else it could be please let me know.

Any help would be greatly appreciated, thanks.

justinc
22nd April 2009, 10:20 PM
Firstly I would remove the oil pressure switch and plug in a test gauge. The OP switch can fail and send the lamp on at lower pressures. You should get at least 12 to 20 Psi at idle, hot, anything up to 50psi cold, at fast idle. IIRC the lamp will illuminate at 7.5 to 8.5 psi.

JC

RoverP6B
22nd April 2009, 10:34 PM
I would certainly second the switch being the most likely cause.

The length of the oil filter won't be a contributing factor.

Ron.