oil pressure light switch

[roverp5saloon]

Hi,

I was wondering if someone can give me some advice. The oil pressure light switch occasionly goes on or flickers. I've had the switch replaced but am unsure if this means replacing the oil pump? Could this be an electrical fault? The oil is fresh as is the filter. 20w 50.

Thanks
Peter

[p5tgc]

The V8 is an engine which has low oil pressure as standard, and it is not unusual for the pressure light to come on when the engine is idling and in drive, as long as the light goes out when the revs rise above 1,000 rpm there is no cause for concern.

[Phil Nottingham]

Yes - quite normal and indeed the handbook even mentions it.

Always ensure oil and filter is changed frequently irrespective of mileage travelled

[roverp5saloon]

Thanks,

Unfortunatly the Saloon doesn't have a rev. meter so I'm not sure what speed that would be. However the odd thing is the light going on and off and the flickering at any speed more often than not at say 60 - 70 mph. The mechanic who looks after her is now saying oil pump failure is rare so he things an engine rebuild is on the cards.

Peter

[Phil Nottingham]

Never pull engines apart unless the easiest/cheapest solution is tried!. The pressure switch does not last long and should be replaced first.

If pressure is really that low at speed there would be other symptons usually like knocking/rumbling, which poits to main/big end bearings or even worn rocker shafts.

If bearings are worn a engine rebuild is not far way but it really depends on the mileage you propose doing

[Phil Nottingham]

The original P5B engine relies and was designed for a low pressure (40lbs max) high volume running 30Ib is OK - the car gauges are calibrated to take account of this. Its quite easy to do this so as disguise a low oil pressure!!

Most other cars including Rovers own 6, 30Lb would be terminal as this should run at 50Lb even my P2 settles at 40!

Cannot speak for later versions of this engine

[theroveringmember]

roverp5saloon said:

Thanks,

Unfortunatly the Saloon doesn't have a rev. meter so I'm not sure what speed that would be. However the odd thing is the light going on and off and the flickering at any speed more often than not at say 60 - 70 mph. The mechanic who looks after her is now saying oil pump failure is rare so he things an engine rebuild is on the cards.

Peter

I had low-pressure a few years back which was cured by new oil-pump internals (& the pressure-switch failed not that many moons later too). The rest of the engine had been re-built a few years before.

[johnwp5bcoupe]

Don't forget they changed the oil pump to a higher volume type on later models and I have been told that it also gave a higer pressure when pc plod ran the V8 the oil was changed in some depots on a weekly basis or 1000 miles which ever came first must tell you something apart from oil is cheaper than a new engine