Thread: 4.6 Oil Pump ?

The pressure relief valve is in the cover near the oil pressure switch.

The pump is non-serviceable. You have to buy a new timing cover and pump.

Late edit: June 2011. The pump is now available as a service item. See later in this thread.

Originally Posted by Jezzaol

My 4.6, Since We did it up a couple of years ago has had low oil pressure at idle, The light comes on sitting at lights etc
Cheers and thanks in Advance !
Jeremy

First question is are you sure your oil pressure is actually low at idle or whether the oil light switch is faulty. Have you checked the pressure with a mechanical gauge???

I have rebuilt an engine with low pressure only to have the light come on in the rebuilt engine. Fix was a switch which is much cheaper.

Regards Philip A

Originally Posted by PhilipA

First question is are you sure your oil pressure is actually low at idle or whether the oil light switch is faulty. Have you checked the pressure with a mechanical gauge???

I have rebuilt an engine with low pressure only to have the light come on in the rebuilt engine. Fix was a switch which is much cheaper.

Regards Philip A

As above, try a mechanical gauge first, if the oil pressure really was that low then a fair amount of tappet rattle will be evident. Also, the oil lamp will usually take ages to go out when first starting if oil pump is badly worn, hot or cold.

JC

I have not checked the oil presure with a gauge but its does get a rattle if you leave it go for much more than a couple of mins !

I gues I will check the pressure relief valve?

Cheers
Jeremy

have had a Td5 with this fault, had manufacturing swarf from ally block brace and oil pick up assembly stuck in the relief valve plunger

Easy fix and caught it before any damage was caused luckily.


JC

Is it a matter of replacing the Relief valve or ??? What should I check or clean ??

Originally Posted by justinc

have had a Td5 with this fault, had manufacturing swarf from ally block brace and oil pick up assembly stuck in the relief valve plunger

Easy fix and caught it before any damage was caused luckily.


JC

Hi Jeremy,

Just remove the plunger and carefully inspect the bore for scoring and evidence of the plunger not seating at it's base, IE at rest it should be able to seal off the chamber completely, and the springs actual tension holding the plunger down is what gives you oil pressure. If the spring is weak or broken, the plunger sticking and not seating that will allow oil to bleed off around it and therefore low oil pressure.

If all looks OK, then I would be dropping the timing cover and checking the pump for scoring and wear on the thrust plate.

JC

Also check the teeth on the gears. They can chew out quite badly.

On reassembly, Loctite the pump screws.