Yes I know the gauge is a bit overkill specially at reading the lower

but after letting the engine run for 40 min pressure was at 15 psi the oil light was on from when I started the truck and these pictures were taken

But last time I checked the pressure at the oil pressure switch port it was not this high the needle was almost touching the stop part on the gauge
tomorrow I will recheck at the sensor port
what if it’s low ???
Why wouid the pressure be different at that port vs this port in picture ???

 

15 psi at idle is fine. The rule of thumb for these old school 50-80's engines is 10 psi per 1000 rpm, so if it idles at 600 you need 6 psi, runs down the road at 3000 you need 30. You might want to check it for giggles at 3000 rpm, I suspect you will have at least 40 psi. Looks like you have a bad sender. That port is the return port for the oil cooler and it tied directly in to the input to the oil filter - the only reason they should read different if if you had significant pressure drop across the oil filter, which is unlikely.

Now, about that permanent dash mounted oil pressure gauge...

 

Well I will check today when I get home and see if pressures change

i also ordered a new sensor from Land Rover as the new one I bought from a local parts store also turned on the light

not sure what the settings are on these switches but it’s worth a shot

now if I do have a drop at the oil pressure switch what’s next ? My oil filter is brand new
Could it be the relief valve ??

 

Relief valve shoudl be closed, if it is stuck open that could cause low oil pressure. Highly unlikely. Relief valve normally opens at about 50 psi, unlikely you have seen that pressure in a long time if ever. If you have a drop at the pressure switch you have a plugged oil filter AND a non-functional bypass valve (not the same as the relief valve). Also highly unlikely.

 

Well this whole scenario is starting to become embarrassing but good news
checked pressure at oil switch all good even when hot it’s 15 psi. So now I don’t have a pressure issue but a wiring or switch issue

likely what happen at beginning was oil light came on. Checked pressure yes it was low
had my landy mechanic replace oil pump and cover
ran good for a few weeks light came on I parked it fearing the worse
now 2 months later I decided to look into it
oil light is on. Pressure is good
I’m replacing the switch tomorrow and see if light stays on it’s somewhere in the wiring Mostly likely when I got my cdl transfer case installed

all and all my disco is healthy

 

My oil light is still on I believe the switch grounds the wire making light come on correct ?
Even with the wire off the switch the light is still on
I’m assuming it’s being grounded somewhere ?
How hard would it be to run a new wire to the switch ?

 

Yeah, the wire is probably clamped under the accessory bracket. Not that hard to run another wire.

 

After sitting for nearly 6 months I finally got insurance on the disco again and took it for a boot. I did miss driving it what a joy
long live the disco

 

Did I see the Disco is up for sale again???

 

i put it for sale but not cheap I’m asking 11 k cnd and only the right buyer will appreciate a good solid disco
ultimately I always wanted a defender or a diesel disco that’s left hand drive so this would be going forwards funding it. But I’ve put so much work into it and really enjoy driving that I really don’t care if it sells