NL oil pressure

[Olly75]

The filters I picked up in FP are made by fleet guard which looking online seems to be a decent quality. I've also put over a hundred hours on the genny since using them (changing every 50 hours) but will go and source one here and change it out.

I already drained the oil before I removed the relief valve as I wasn't sure how much would spill when I removed it so will top up with new anyway and also prefill the filter before installing.

[Wotname]

Originally Posted by Compass790

How many hours on the engine? Sorry if it's been posted & I missed it but I'd be checking oil pump tolerances after other tips by previous posters if it's a high hours engine.

Here you go

Originally Posted by Olly75

@wotname, it was from a cold start, there was no load on it and she's only had (allegedly) 540 hours running time.

.......

[kmacdonald]

Fleet guard are good filters. That's Cummins.

[Olly75]

Possibly clutching at straws here, but I have recently replaced the water pump and also adjusted the valve clearances. I ran it afterwards- albeit briefly- to check it was working fine and there were no problems, but just wondering if this could have had an impact?

[skipperpete]

Because it’s yet another slow day in lockdown and that very low lube oil pressure is about the most serious thing that can happen to an engine ( especially a generator engine)I opened up a fram spin on from a NL 643. Its a full flow filter with a relief valve on the bottom and a non return valve on the top and I can’t see how or what in the filter could cause low lube oil pressure. If the bypass valve failed, unfiltered oil would still flow and it’s hard to see how the big non return valve could block the flow[emoji845]
However, I would still change the filter and then.... because there ain’t much to do really.... I,d open up the old filter and unfold the paper element in a search for metal particles that might indicate a deeper fault. The oil pressure alarm switch operates at 4.3psi.

[a64pilot]

I believe he said 540 hours just barely broken in

[a64pilot]

Originally Posted by skipperpete

Because it’s yet another slow day in lockdown and that very low lube oil pressure is about the most serious thing that can happen to an engine ( especially a generator engine)I opened up a fram spin on from a NL 643. Its a full flow filter with a relief valve on the bottom and a non return valve on the top and I can’t see how or what in the filter could cause low lube oil pressure. If the bypass valve failed, unfiltered oil would still flow and it’s hard to see how the big non return valve could block the flow[emoji845]
However, I would still change the filter and then.... because there ain’t much to do really.... I,d open up the old filter and unfold the paper element in a search for metal particles that might indicate a deeper fault. The oil pressure alarm switch operates at 4.3psi. Attachment 215089

The media can collapse or I swear the one time I saw it I think they left the media covered in plastic or similar. I didn’t cut it open or inspect it, it was someone else’s boat that he “fixed” his low oil pressure with a filter change.
Some of the bargain off brand filters may not have a bypass valve or a drain back valve.
I believe he sourced it in Singapore or simiar?
Nut for $5, why not give it a shot, maybe he will get lucky. On a 500 hour engine, there really shouldn’t be any reason at all for 5 PSI oil pressure at I assume 1500 RPM on cold oil.
If he didn’t install a direct reading gauge, I’d be suspect with that number, but he has a low PSI problem, and installed a direct reading gauge, if I followed the thread correctly.

[a64pilot]

Originally Posted by Olly75

Possibly clutching at straws here, but I have recently replaced the water pump and also adjusted the valve clearances. I ran it afterwards- albeit briefly- to check it was working fine and there were no problems, but just wondering if this could have had an impact?

I don’t see how, valves if too tight you will lose performance, but no effect on oil pressure, especially not cold. Too loose and they rattle but again no oil pressure change.
If it was running stinking hot as in boil over hot that will drop oil pressure, but to 5 PSI? and you got that I’m assuming on a cold motor, you didn’t run it long at that pressure?
So even assuming you messed up the water pump change it shouldn’t matter.
You had to change the water pump on a 500 hr engine?

Just read the Fleet guard comment, unless they were counterfeit, They are an excellent filter, up there with NAPA gold, Wix and some others.

[skipperpete]

If it does come down to being a faulty oil pump, give the thread a heads up before you try to tackle the job yourself. Its not a terribly difficult project but there are a few things you really need to know that will save you hours of work.... that aren’t mentioned in any service manual.

[Compass790]

Originally Posted by Wotname

Here you go

Ok thanks Wottie & A64,with those low hours shouldn't be oil pump.
HOWEVER I bought an engine with 463 hrs ( didn't believe it ) & a way over tolerance oil pump. I think I'd still be checking the oil pump, more likely than filter failure but easier & logical to check filter failure & PRV first.
Pity it's a PITA to get at. Very curious to see how this one pans out

To OP. Has the engine suddenly become very noisy? Agree with all the other posters not to run for any length of time with such low oil pressure as you risk catastrophic engine damage. Ask me how I know?

[kmacdonald]

Did you have to adjust the valve lash a lot or was it close? I have never seen or heard of a confirmed oil pump failure even on high hour engines. The oil doesn't have a diesel smell to it does it? Did you adjust the valves as preventative maintenance or to correct an issue?

[kmacdonald]

If this low oil pressure happened all the sudden, it's not a wear issue but a failure issue. Oil pressure will decrease very slowly with wear but 5 psi would never happen. I didn't find any hits in google about that engine and low oil pressure. You might want to see if there are any technical bulletins about that problem. If I were you I'd recheck the valve lash if that's the last thing you did to the engine.

[Olly75]

So took off the filter, cut it open and took out the membrane for a look and no visible signs of any metal bits in it.

Replaced with new filter, loaded up the oil and started it, and still getting an oil pressure of 5psi...

I barely adjusted the valves, and only had a look at them as the manual says check every six hundered hours. As its lockdown I had a bit of time on my hands...!

When I say 540 hours, this is what is showing on the clock, but the genny was installed in 2003 which is why Im a little suspicious of the hours (that and a number of other things have had to be worked on since I took ownershipt- exhaust elbow, exhaust temp over heat sensor, injectors, bushes and the AC AVR. I replaced the water pump as it started leaking and while trying to repair it I broke it even futher

Also, and this may have a bearing on the issue, the genny had been sat unused for around four years when I bought the boat.

[kmacdonald]

But it ran well with good oil pressure?

[Olly75]

Originally Posted by kmacdonald

But it ran well with good oil pressure?

Alas not, still only getting 5psi...