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low oil pressure

PostPosted: Sun Jul 18, 2010 7:07 pm
by super6
what do i need to look at first on my ford 6 cylinder engine, it is an idustrial versoin of the d series lorry engine.
pressure is about 20 psi at 1000rpm when cold, and drops to 5 psi when hot, it will increase with revs.
i am currently using a standard 15w40 diesel oil.
I does breathe a bit from the rocker cover breather if thats any help.

PostPosted: Sun Jul 18, 2010 9:25 pm
by Brian
What does it get up to when hot?

It could be worn oil pump or everything from the crank and bearings to camshaft and bearings.

It will be a 2700 series engine as used in combines etc.

PostPosted: Sun Jul 18, 2010 10:14 pm
by fergusont20
Our internationl B250 oil pressure is not as high as i would like, when i get the chance i want to do some investigative work, im starting with the pump as i suspect the gears inside it may be worn. But as Brian suggests i could be several things.

Have you got a book to help you check clearances, measure tolerances etc ??

Let us know how you get one, my 2700 series appears to have quite good oil pressure, even with the old oil and filter of around 40 psi when warm.


PostPosted: Mon Jul 19, 2010 2:20 pm
by super6
what sort of revs are you doing to get 40 psi.
i am not all that familiar with the inside of engines, where is oil pump and how hard would it be to change as a novice mecanic.

PostPosted: Mon Jul 19, 2010 5:27 pm
by fergusont20
Bearing in mind I don't know the exact workings of these model of engines, and I havnt yet done anything to mine

Drop your oil, take the sump off, your oil pump will be just inside, take it apart, but remember or photograph how it goes back together,all are built on same principle but each is slightly different. Anyway there will be a couple of gears which turn and pump all the oil from sump all around engine, you really need a workshop manual to know what the spec is but check the gaps between the meeting teeth, these gears may be worn and not pumping enough oil around

If worn you can replace the whole unit or get an overhaul kit, I'm not sure where you can get parts from for these engines though

Let us know your findings


PostPosted: Mon Jul 19, 2010 5:43 pm
by Brian
The problem is the gap all around the outside of the gears and housing as well as the teeth. The oil is carried around the outside and if there is too much clearance it won't help.

There should also be a pressure relief valve on the pump. You may find a weak spring here too.

Re: low oil pressure

PostPosted: Sun Jun 19, 2011 5:21 am
by 1962 model
I can't remember how those industrail engines are set up, but if it is the same as the Fordsons, low oil pressure can be from diluted engine oil.

The Fordsons should have copper washers on both sides of the bleed off return pipe banjo fittings and the solder must be also in good order too or they will leak diesel into the engine oil.

I just had a pump apart and the end plate was worn, if yours is like this one you could try having the end plate refaced, but as has been said if the clearance between the outside of the gears and the housing is excessive the pump really needs a rebuild.
The bearings could be worn too, maybe you could fit new bearings while the sump is off if the crank is servicable?