Thread: D2a Low Oil Pressure

Could be the pump, but it could also be worn bearings, which IMO is more likely. Could be wrong,but I’d budget for a rebuild.

Low oil pressure is pretty much always caused by 1 or more of the following:

Worn oil pump.

Worn out or incorrectly adjusted relief valve.

Worn main bearings

Worn crank.

And at a stretch... The wrong oil

I know NOTHING about the V8 at all, but if possible without too much work, the Sump could be removed and the bearings checked.
Some engines can have the main bearings "rolled in" without removing the crank.

Not all can have this done, but I'm positive someone on here will know if it's possible.

If it's the oil pump, I doub't that 35psi at 2000rpm is dangerously low and will have caused major damage, so you may get away with just replacing that.

Cheers
James

At nearly 300,000km I say it will be your main bearings. I pulled V8 down at 235,000km that had been well looked after and the bearings were down to the copper.

But 10psi at idle and 35 at 2000rpm is enough oil pressure for a Rover. Is the fault just with your oil pressure switch?


Des Hammill's book How to Power Tune RV8 Engines is very illuminating on this aspect. For example, he quotes the following as being reasonably expected pressures from a rebuilt pre-serp road going RV8:
1000 rpm = 10psi
2000 rpm = 28psi
3000 rpm = 32 psi
4000 rpm = 38 psi
5000 rpm = 40 psi

Thanks guys, I think I will start enquiries with an engine re-build. The oil pressure switch was replaced, so unfortunately wasn't that. I can't justify the money for the oil pump replacement, I have been using the car every day for work, so I think I will retire it from work and slowly fix it up so it becomes my going away/4wding car only. Had been looking at the new Ineos Grenadier but they, like the newer Land Rovers are out of my consideration price wise.

Cheers,

Vinnie

Originally Posted by Vinnie

Thanks guys, I think I will start enquiries with an engine re-build. The oil pressure switch was replaced, so unfortunately wasn't that. I can't justify the money for the oil pump replacement, I have been using the car every day for work, so I think I will retire it from work and slowly fix it up so it becomes my going away/4wding car only. Had been looking at the new Ineos Grenadier but they, like the newer Land Rovers are out of my consideration price wise.

Cheers,

Vinnie

Hi Vinnie, I think if you read FisherX's post, it shows that your figures are bang on for a healthy Rover V8 engine....

Not all engines run the same oil pressure, it's possible that you have fitted a generic pressure switch that is the incorrect one for that model of engine.

It's happened before... And your pressure readings seem to qualify that is the case.


Edit...

Just double checked RAVE oil pressure minimum at idle should be 10psi.

At 2000 rpm it should be 50psi, but no more than that as the relief valve opens at 50psi

The switch should put the light on at 6psi.

Originally Posted by shack

Hi Vinnie, I think if you read FisherX's post, it shows that your figures are bang on for a healthy Rover V8 engine....

Not all engines run the same oil pressure, it's possible that you have fitted a generic pressure switch that is the incorrect one for that model of engine.

It's happened before... And your pressure readings seem to qualify that is the case.


Edit...

Just double checked RAVE oil pressure minimum at idle should be 10psi.

At 2000 rpm it should be 50psi, but no more than that as the relief valve opens at 50psi

The switch should put the light on at 6psi.

Thanks Shack, I will look into it. I know my mechanic put an aftermarket switch on at first, but then we put a genuine one on. I will follow up with him and maybe try a new switch, maybe I will speak to a mob like Ritter's and see if they have one in stock and try that 1st.

The idle pressure seems about right, but the higher rpm might be a bit on the low side...

But That's your call!

I would,if possible fit an oil pressure gauge,then run the engine and see what pressure the light comes on at.

That will let you know more about what is going on.