Rover V8 Oil Pressure Issues when cold

[RoverV8Nut]

Hi there,

I'm looking for some advice regarding my 3.9 Rover V8 in my Defender.

I have oil pressure issues when starting from cold. in the winter it takes approx 10-12 seconds to get oil pressure from cold start and in summer around 6 seconds. I live in Scotland so winters aren't exactly arctic. I use 20w 50 classic oil.

I have changed the oil pump internals (gears), heavier spring, oil pressure sensor & oil pump casing. (old style external oil pump)
I have also dropped the sump and cleaned the oil pick up pipe and cleaned the sump and replaced sump gasket.

I have a fear it might be the bottom end that is worn but is there anything else I can do to improve the oil pressure on start up?
When the engine is running the light never comes on again.

At the moment I am disconnecting the ECU and turning it over until the oil pressure light goes off then starting it, which isn't ideal.


Thanks in advance.

[RoverV8Nut]

paintman said:

A quick look on LRcat suggests there is more than one pressure sensor.
http://new.lrcat.com/
I'd suggest you look into that to be sure you've got the right one AND a good quality one not one of the cheapies.
AND
consider fitting an accurate oil pressure gauge in lieu of the sensor so you can see what the oil pressure actually is.

These aren't a particularly high pressure system but do shift a high volume.

Paintman,

Thanks for your help. I will look into this. I can't remember if I bought a decent quality one or not but I'm sure I bought it off of Rimmer Bros.
But I will try find a genuine one and replace it.

[RoverV8Nut]

chammyman said:

Thinner oil in the winter.

20 50 is fine in the summer.

My 4.6 thor currently has 5w30 fully synth in it

Hi Chammyman,

I thought they needed to run zinc rich oil to prevent wear to the cam? Do you add zinc additive?