What can cause low oil pressure at engine idle?

[Ollie]

I've just replaced the Zeus timing housing and gears with standard Land Rover housing and cam belt. As part of the kit I installed a new oil pump.
I had the sump off and installed a new pump pickup o-ring too.
The reason for replacement was the Zues gears sheared teeth and ceased, causing a few bent push rods and a broken rocker :oops:
I replaced the oil, (semi-synth 10W40), and oil filer too.

Since then I get a low oil pressure warning light at idle, (about 900rpm), if I blip the throttle to 1100rpm, it goes out.
There's no apparent oil loss, and the dip stick shows nearly full.

As I don't understand the oil system in the car, I'm at a loss as to where to look :-k

Any pointers please

Ollie

[solihull-mick]

First simple test change the pressure switch, after that i would get a gauge to see just how much pressure you do have, could be sign of worn main or big end bearings, i have a 300 disco in at the moment with the same fault, turns outs its the main bearing on the crank, good luck 

[Ollie]

I've ordered a new switch, change that on Wednesday.
Hope it's nothing else :pale:

[Saffy]

Out of interest, what was the mileage on the Zues gears?

[Ollie]

About 40K, reg service every 6k miles, drive like Miss Daisy!

[Ollie]

Could someone please explain the route of the oil from the sump> Oil Pump > Then where?????????
Would help me understand where my problem might be

Cheers
Ollie

[Saffy]

Could someone please explain the route of the oil from the sump> Oil Pump > Then where?????????
Would help me understand where my problem might be

Cheers
Ollie

You have a 300tdi I think, Purchase the 300tdi engine overhaul manual, it details what you need to know.

For reference:



The engine lubrication system is of the wet sump type, oil pressure being provided by the rotor type oil pump (1) driven directly by the crankshaft.

Oil is drawn from the sump (2) through the strainer (3), suction pipe (4) and passes through internal drillings in the cylinder block to an external, full flow filter (5).

Further drillings feed oil to the cylinder block main oil gallery (6) which, in turn, supplies the crankshaft main bearings ( 7 ).

Cross drillings in the crankshaft carry oil to the connecting rod big-end bearings ( 8 ).

The camshaft bearings (9) are supplied with oil from the main oil gallery.

An internal oilway from the camshaft front bearing connects the cylinder block to the cylinder head and feeds oil to the rocker shaft assembly (10), lubricating the valves and springs.

The pistons, gudgeon pins and small end bushes are lubricated and cooled by oil jets (11) which are supplied from the main oil gallery via relief valves which allow the oil to flow at a pre-determined pressure.

Oil pressure is controlled by a pressure relief valve (12) incorporated in the timing case housing together with the oil pump. The valve allows excess oil to be recirculated back into the oil feed gallery.

The rotor type oil pump is driven by 2 flats machined on the front of the crankshaft.

Oil cooling is maintained by an oil cooler which is integral with the radiator and linked to adaptors on the oil filter head by pre-formed feed and return hoses. A thermostatic valve in the filter head allows oil to flow to the cooler when it reaches a pre-determined temperature.