Oil Pressure Fixes

OIL Pressure fixes 2.3 Diesel 2.4 Petrol

The oil relief valve on the holden engines 2.4 petrol and 2.3 diesel has a alloy casting, a fibre bush and a spring the bush is of a harder material and wears the casting also the oil pump rotors run on the casting causing scoring .

These two problems lead to low oil pressure with oil flowing past the relief valve and casting material in the oil pump.

If you replace the oil pump relief valve housing an instant rise in oil pressure is found.

This cure has been known since the introduction of the engines on MK1 cavaliers Bedford CF vans VX carltons VX royales and senators. It is known to be the cheapest way to get oil pressure back, it does not cure the following:

Back pressure caused by piston slap (new rings required).

Wear in crankshaft ( regrind required).

The plus part about replacing the oil pressure relief valve plate assy is that it can be done in situ without major strip down.

Diesel 2.3 Only

Examine the filter adapter it  has sometimes been found that the pin that pushes the thermostat open, push through the base of the thermostat.

This can be seen sticking out of the base by the spring, remove the circlip and prise the cap out by putting an allen key inside the hole in the adapter.

By pushing from inside it is possible to remove it even when it is solidly stuck, after getting it out and replace the thermostat and o ring seals.

By replacing everything the oil cooler will work fine

Things to note:

Make sure the pipes from the oil cooler don't get switched round, hot oil flows into top of cooler and back to filter from the bottom.

An easy way to prime the pump is to do it before you replace filter adapter by pushing a small bit of hose down the pipe, this pipe comes from the oil pump and squirting oil into pump using an oil can on the other end of the hose.

When oil drips out of the hole where the adapter plate goes( not the big one in the middle the one to the side and quite high up inside) let it stand for a while.

Fill some more it takes about as much as a coke can holds, about 300ml, the pump should then be full by then and ready to go.

Once everything is back together , pull the wire on the fuel pump solenoid and turn engine over a few times until oil light goes out.

Re attach wire and start her up and take her for a spin.

Do not forget to check your oil levels as well before you start the engine, as you will get a false low reading

If you check after  the engine has been running.

 Thanks to Jason for 2.3 diesel oil cooler info