Possible Oil Pressure Issue (1 Viewer)

[zonker]

Recently I got an oil sample result back that shows excessive wear. Chromium.. iron.. copper.. etc. Pretty much discounted it. Talked to Blackstone and they admit it could have been mixed up with someone else.. but highly unlikely. The LC has 109,000 miles.. sounds perfect.. gets standard MPG and only burned about a quart of oil in 5,000 miles. When I changed the oil at 5,000 it was fairly clean still. Not a candidate in my mind for excessive internal wear.

Installed a VDO oil pressure gauge.. just because I like them and the OEM gauge tells me nothing. Besides if pressure is low.. I really want to know NOW. So the results after driving it for enough time to get those numbers has me a bit worried that there is a problem.

50 degree day.. 185 degrees for the coolant. At idle I am under 5 psi.. guessing probably 3 and change. At 3,000 rpm 39psi. As is probably known by others.. FSM = 3.9 psi at idle and 36-71 psi at 3,000 rpm. I got a solid 40 out of it at about 3,300. This is with Mobil One 10w-30. Wix XP filter. Zero miles on a fresh change.

I certainly don't like hanging out at the low end of the spec. SO do I need to dig into this and get the pressure up and inspect main bearings. Or are the psi numbers I have good and I am just being silly. The other side would be that the Blackstone sample was not mixed up and I am looking at a full rebuild if I don't get the PSI up and soon. Maybe looking at a rebuild anyway.. especially if a compression and leak down indicate it is so. Head gasket is solid. No coolant or other particulates that would indicate a loss of sealing.

Opinions asked for and appreciated!!

 

[inkpot]

What brand/weight oil and how many miles on the oil?

 

[zonker]

Oops.. forgot to post that important footnote. Original post updated.

Mobil One 10w-30. Wix XP filter. Zero miles on fresh change.

 

[Cruiserdrew]

Use Mobil 1 15w-50 and report back. Or, Mobil 1 5w-40, or Mobil 1 Turbo Diesel Truck or what ever they call it now.

The oil pressure readings with Xw-30 always look low. And Mobil1 10w-30 is on the light side of a 30 weight.

Seriously, you are probably fine. Your oil analysis is making you nervous. That's the problem with oil analysis. My guess is the previous owner didn't change much and you're seeing the accumulated results. Send in another sample after 3 changes of Mobil 1. I'll bet all is well.

But seriously, use a thicker oil. And a real test gauge.

It is possible you have engine problems, these are 20 year old trucks after all, but only burning 1 quart in 5K miles and running with good power suggests all is well.

 

[zonker]

Another bit that might shed some light on why I am very concerned and why I started with oil pressure. Here is the PDF oil sample report.

 

[zonker]

Thanks CruiserDrew for the reply. I will drain and refill with your 15w-50 or TurboDiesel which I do have on the shelf. I assumed that since the FSM advised 10w-30.. life was good. Also will use my direct to engine oil pressure tester. I wanted a real world test with load. Hence my using the installed gauge. Advice taken however.

The previous owner had very solid records that indicated that the oil had been changed every 3700 miles average. They were the owners from 37,000 until 105,000 when I purchased it. However as we all know.. there could always have been a fly in the ointment that fails to get mentioned!

 

[OGBeno]

I'd go heavier oil first: Rotella 15-40 or Delo 15-40 and see if there is a change.


That said, I think the pressure is fine.

 

[Cruiserdrew]

Your sample report says you suspect HG problems. Why is that?

If your HG is bad, you'll need to fix that asap before worrying about wear metals.

And yes, the head gaskets need to be replaced if you are still running the factory one. Just do it.

 

[Kernal]

^^^This^^^

 

[zonker]

Thanks for the great feedback. First a little bit about myself which will circle me back to now. I am a shade on the obsessive side when it comes to things working perfectly. Spent about 10 years working as a factory trained BMW tech. This type of machinery worked well with my personality. Most of it was fairly new and definitely not 20 years old. But my true love would be LandCruiser's as I started driving life with a FJ40. So now I am back where I belong with an 80.

Now to tie the previous paragraph to my 80 and the oil pressure potential problem. Early on I detected the very slight beginnings of a head gasket after a 2200 mile round trip to the Mojave over Xmas. Pulled the oil sample as that is the easiest path. I knew a compression test and leak-down were next depending on the sample results. WOW was I shocked when the results came in. My thought.. there was only one thing that would cause that much wear.. OIL pressure. I was using the Toyota spec oil grade.. so had to look deeper. The HG went on the back burner as I pursued knowing what the real world oil pressure was.

Now.. here I am with 8 quarts of 15w-40 Rotella. I will do an oil change and as I expect the oil pressure will come up. Never would have crossed my mind to go that far outside of spec on the oil. After I see that oil pressure is good.. I will go back to the head gasket discovery. More than likely I will change it out as a PM function.. unless it is REALLY solid and I see no more little signs. I know there are several trains of thought on the HG as PM. However I would rather change in the comfort of my own shop on my own time.. rather than getting home from some remote location after it definitely goes on a 100 degree day. I like my extended trips to be fun and not have to worry about fixing stuff.

Thanks again Inkpot.. CruiserDrew.. Beno and Kernal for your time to post on my issue(s).