Defender91 · Jul 2, 2020

Hi,
Thought I'd update,finally got time so going to take the engine out tomorrow afternoon and start looking for the fault.
Will post if/when I find what was wrong.
Thanks for all the help.

steve2286w · Jul 2, 2020

Good luck let’s hope it’s a cheap fix easily spotted

TR3a · Jul 4, 2020

In my experience a big difference in oil pressure between hot and cold is usually down to worn main bearings.
Did you have the crank reground or just fit new shells........are the shells correct for the crank journal size?

Defender91 · Jul 5, 2020

No, I didn't get the crank ground,measured all the journals and they matched the manual so got standard shells.
Had a look at the mains and big ends and don't show much wear. All the oil jets are intact as well.
Thanks

TR3a · Jul 5, 2020

If it isn't the bearings then it is most likely associated with the oil pump.
May be the pressure relief valve is not on its seat or the spring weak.

Obscure but been known is a collapsed oil filter.

Defender91 · Jul 6, 2020

I'll strip the oil pump down and check for the things you suggested,it was putting out plenty of pressure when cold though so don't reckon it's the relief valve.
It's had several oil filters since this problem, I didn't notice any difference between them.
Thanks for suggestions,it's going to have to go on hold for this week but I'll continue stripping it at the weekend.

lynall · Jul 6, 2020

Defender91 said:
I'll strip the oil pump down and check for the things you suggested,it was putting out plenty of pressure when cold though so don't reckon it's the relief valve.
It's had several oil filters since this problem, I didn't notice any difference between them.
Thanks for suggestions,it's going to have to go on hold for this week but I'll continue stripping it at the weekend.

As you have it in pieces, it may pay to get some plastigauge and check all the bearing clearances?

I cannot remember if it was mentioned before, has the cyl head oil feed got a built in restrictor?

Defender91 · Jul 7, 2020

Will do, I'll order some.
Not sure about the oil restrictor,but that would make it lose pressure throughout the temperature range wouldn't it?

lynall · Jul 7, 2020

Defender91 said:
Will do, I'll order some.
Not sure about the oil restrictor,but that would make it lose pressure throughout the temperature range wouldn't it?

What I was thinking was cold oil thick hot oil thin, and oil is like electricity lazy, and will take the easiest route to freedom at every oppurtunity.

If it has a restrictor it may be in the block, the head, or the head gasket?

Looking at oil flow chart, and it appears valve train oil feed comes from the front camshaft bearing feed, up though the head and into the rocker shaft, so got to be worth a good look at the shaft and rockers to see if any wear present, thinking to much wear=to much clearance, stretching I know but whilst you are in there.

lynall · Jul 7, 2020

Just found a post where guy reckons piston oil sprey jets are held on with banjo bolts and they have a restrictor built in that opens at 26psi, cant see it mentioned in the manual though?

steve2286w · Jul 7, 2020

When I did mine I thought the banjo bolt looked a bit odd , rumour has it there is a spring and ball in the bolt , And a check to press ball in se if it works ok, fitting washers is important , perhaps if you’re in there would you get a pic

Defender91 · Jul 7, 2020

I remember the piston jet bolts as I had to get a new one after it sheared.
Apparently the oil restrictor is built into the head gasket.
Can't get a photo of the cooling jets at the moment, but I remember that they did at a strange angle as they had to locate one the block.
Did check the rocker shaft a while back,it was slightly worn but within the limits on the manual, did notice there was a lot of oil flying around in there when running though.
Thanks for the replies.

Defender91 · Jul 26, 2020

Hi,
Sorry it's been so long between posts, work has been very busy recently.
Checked the piston cooling jets and all were ok,they were all firing about 20-22psi.
Had the oil pump apart,the relief valve seems alright but the endfloat on the gears is a fair bit more than the manual.
Endfloat : 0.20-0.25 mm
Meant to be 0.02 to 0.13mm
Is this a possible cause? Last thing I want to do is to think I've fixed it and put it all back together in the landy to find it's still got the fault.
Thanks

TR3a · Jul 26, 2020

Defender91 said:
Hi,
Sorry it's been so long between posts, work has been very busy recently.
Checked the piston cooling jets and all were ok,they were all firing about 20-22psi.
Had the oil pump apart,the relief valve seems alright but the endfloat on the gears is a fair bit more than the manual.
Endfloat : 0.20-0.25 mm
Meant to be 0.02 to 0.13mm
Is this a possible cause? Last thing I want to do is to think I've fixed it and put it all back together in the landy to find it's still got the fault.
Thanks

That certainly won't help. I should measure the radial clearances between the gear teeth/rotor and the casing, if that is excessive it won't help either.
In any case, I would not put it back with that amount of end float. It is sometimes possible to machine the casing to restore the correct end float but if the gear/rotor to casing clearance is bad then fit a new pump.

As you have confirmed that the bigend and mains clearances are ok then that really only leaves a worn oil pump as a major contributor to a big difference between hot and cold oil pressure.

Your pressures were not a million miles away to start with......I would go for the oil pump. In your initial post you said that the pump was new.......so has it worn to give excessive end float or was it a cheap knockoff that was made that way?
I am no expert on LR deisel engines but would suggest that the oil jets that keep the pistons cool are the biggest contributor to loss of pressure when hot.....most engines rely on oil escaping from the bigends and being thrown around by the crank for piston cooling and bore lubrication..... if your pump was dimensionaly correct this might be enough to get the pressures within spec.

Hope that this ramble helps....

The other thing to check is the crankshaft end float........if excessive, more oil than designed can escape from the center main bearing via the thrust washer clearance.

lynall · Jul 26, 2020

Defender91 said:
Hi,
Sorry it's been so long between posts, work has been very busy recently.
Checked the piston cooling jets and all were ok,they were all firing about 20-22psi.
Had the oil pump apart,the relief valve seems alright but the endfloat on the gears is a fair bit more than the manual.
Endfloat : 0.20-0.25 mm
Meant to be 0.02 to 0.13mm
Is this a possible cause? Last thing I want to do is to think I've fixed it and put it all back together in the landy to find it's still got the fault.
Thanks

Well that is double the max spec, so needs replacing.

Do Truners do 200 pumps?

steve2286w · Jul 26, 2020

TR3a said:
help either.
In any case, I would not put it back with that amount of end float. It is sometimes possible to machine the casing to restore the correct end float but if the gear/rotor to casing clearance is bad then fit a new pump.

it’s only 3 thou out of spec ( in old money) which you can get back by some wet and dry on a sheet of glass I can’t see it making that much difference but while engine out all the bits needs need checking to see if any other likely causes

TR3a · Jul 26, 2020

Have you checked the suction side of the oil pump to see if it is sucking air.
Are the camshaft bearings good.
I would double check the main bearing clearances, you can get an idea by cutting a strip on thin paper, the thickness of which you can measure with a micrometer and trapping it between one main bearing shell and the crank journal and then seeing if you can turn the engine, although Plastigauge is best as it gives you an absolute measurement.

Is your oil pressure gauge ok.

Defender91 · Jul 26, 2020

Hi,
Thanks for the replies,
It sounds like the general consensus is that I need to keep looking.
Will get the cam out tomorrow evening and go from there.
Thanks

Defender91 · Jul 29, 2020

Hi,
Just in the process of removing the cam this evening, there is an oily residue underneath the front timing cover housing.
Should any of the holes be plugged which could be leaking oil?

Thanks

steve2286w · Jul 29, 2020

This was mine stripped down, I

can’t recall how oily it was beforehand the two oil gallery plugs should not leak
Are the other holes blind tapped / dowel holes
The seals for cam and crank are in the cover so it might be normal for some to seep past , did a lot of oil pour out when cover removed

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