oil light slow to go out

[waxer]

Gday everyone,a little concerned by the oil light staying on after start up ,for quite a while(at idle) when the Defender (1994) has sat unused for a couple of days.Oil level is correct ,fresh oil(synthetic) new filter.Eventually it goes out and stays out.If starting from warm or even after several hours the light goes off quite quickly,never has come on during normal driving.Filter is a Bearmach I think and oil is Caltex full synthetic. Have changed the oil pressure switch recently ,as the old one failed completely(this seems to have only started since then).Could be paranoia but engine seems rattly during this light on period until it goes out.This makes me think it is taking longer to get pumping.Any advice would be appreciated,maybe it doesn't like being left for a couple of days!

[Sitec]

Swap that filter out for a decent Mahle or similar with an anti drain back valve and c how u go...

[roverrescue]

Although I dont disagree on the use of good filtration, I think an ADBV on a 300tdi will most likely not fix your woes the oil pump does not tend to lose prime due to its location on the crank down low.

If the switch is good and not telling lies, then could either be top end or rings perhaps not sealing (does it use oil?) this is less likely.

More likely is the pressure relief valve ( easy to get to with sump off)
or actual oil pump wear...

S

[waxer]

Thanks for the replies.Engine doesn't use oil and seems to have reasonable get up and go.I guess the next step will be to replace the valve ,and then the pump.Not sure which brands of filter have the anti drain back,but probably wouldn't hurt to look into that as well.I think this is the first Bearmach I have had on the old girl.Thanks

[2stroke]

My tdi did exactly this, eventually found that it had a mark in the oilpump housing (part of the timing case) caused by a burr on a tooth of the inner rotor, I assume someone dropped it "after lunch at pub". I cleaned the housing thoroughly and fixed it with some type of liquid metal and replaced the rotors. The many other things I tried didn't.