Ja defender

Yes the bearings were still in excellent condition, so I reused them.

Folks, I finally found he source of my low oil pressure problem. Someone in previously trying to seperate the number one main cap, used a punch type tool to hit the block just below the cap. This resulted in the creation of a bulge or dimple on the fact of the area where the main cap sits. The size of the bulge created a bearing the crank clearance of .008 in, where the limit is .004 in. To correct the problem I used a file to make the area level again, allowing the main cap to sit properly. The mistake I made was not checking the clearances on every journal previously. What I had previously done was check the rear and middle caps as the crank was just cut to .0010 in undersized. On my second measurement of the clearances I made sure to check the clearances on every bearing. After reassembling the engine I now have 27 psi oil pressure at idel with the engine at normal operation tempature. I want to thank you all for your suggestions and interest and stand ready to share the knowledge I have gained in investigating this low oil pressure problem.

Yes I have checked both the relieve valves in oil pump and the ones for the oil jets. I have even gone furthers by r eplacing the entire oil pump.

I have already replaced both the o-ring on the outside of the skew gear and the internal one which seal the outside of the vacuum pump. I thank you for the thought nerve the less and welcome any other thoughts you may have.

I have looked long and hard and I have not yet found any cracks and none of the blank off leaks. The search continues.

I am in the process of investigating the rocker feed and have removed the head. I am a little puzzled at my findings as on removing the head there was some oil on both sides of the gasket in the vicinity of the restrictor. All bolts were tight and both the head and block have checked out fine without any distortion. Any thoughts on this, is this normal? The current cam bearing is the older type with the larger hole going up the the rocker. I am about the replace that with the newer design bearing with the smaller hole. I have been reviewing the vacuum pump and have noticed the pump uses oil pressure to extend the vanes. Could a less that perfect vacuum pump contribute to my low oil pressure problem? Has anybody experienced a problem like this associated with the vacuum pump?

Although I am sure the cam bearings are intact I am now wondering if these bearings are worn. Can anyone say what the effect of worn cam bearing on the oil pressure? I am really concerned about the change in the oil pressure as the temperature increases.

The problem started before the head was removed. I got the engine with this problem, although the vehicle was driving the oil light switch was not working. I pull the engine apart after replacing the switch and found the light flickering at idle. I took the engine apart but found nothing unusual during my examination of the engine then. I am now in the process of doing a more detailed examination of all the suspected areas with the hope of finding the reason for the low oil pressure during normal tempature idle.

Thanks, I am now about to turn my attention to the upper half of the engine. Do you have a photo showing where this restrictor is or know the size of the oil Chanel in the in the head? I refuse to be beaten by this problem and intend to continue until the source of this problem is found. I therefore welcome any ideas on the possible problem

There is in fact a relive valve in the banjo bolt which secure the jets to the block. I actually used a air compressor to determing the opening pressure which turns out to be about 26 psi. That discovery has just added one more possible contributor which I now know is operating fine. My camshaft bearing are in place and have not moved, how do I however check their clearances? This low oil pressure really has me challenged.

What's the best way to check the relieve valves on the oil jets?

Both main and con rods were .0015", measured with plastigauge.

I had consider the lost via the turbo and disconnect the oil feed from the turbo and blocked it off, still no improvement in the oil pressure. I am using 10w-40 oil. I will look at the washer on the stat however do you have any idea how the oil spray jets work. I also wonder if it is possible for oil pressure to be lost from these jets?

That's what I had noticed as in the manuals it appears to be between the pipe and the pump however it was really fitted on the pickup pipe. I have used the diagram and I have gone over all the possible problem areas with the cam, crank and turbo checking out okay. Could a leaking or ill fitted oil jet cause the lost in oil pressure I am experiencing?

Just on a point of clarity, does the O ring for the oil pickup pipe fits on the pipe or between the pipe and the pump body. I have noticed the manuals showing this o ring in front of the pipe rather than over the pipe, between the washer and the pipe flange, which is where I have mine installed.