Low oil pressure - am I okay?

BC_CRDtom · **Posted:** Wed Jun 14, 2023 12:56 am

Hi guys, just finished installing a bunch of suspension, brake & steering components, glow plugs and a bunch of stuff. Get her back on the road and she feels good, all upgrades & new parts working as they should, then I get the oil dash light/ low oil pressure idiot light.

Swap out oil for new 0w40 Rotella and M1-209 filter (was using a FRAM before), still getting it coming off at idle when warm, but also doesn't go away when I increase revs.

Parked her, ordered a manual pressure gauge, hooked up and was very unhappy to see about 5-7psi at idle when 1/4 warm, just idling in the shop for about 5 mins. When rpms increased to 3000 I get 28-30psi.

No weird noises, no smoke, when I open the oil filler cap I can feel a light spray of oil particulate over the filler neck, so I think the top ends getting oil.

Should I be worried? I think I've exhausted all diagnosis items short of dropping the pan (which I've heard is a bunch of work).

Any ideas?

WWDiesel · **Posted:** Wed Jun 14, 2023 1:00 pm

Easy fix!
Install new oil pressure switch, they can and do go bad. Had to change mine a fews years ago due to dash light coming on falsely.
AutoZone Duralast Part Number: PS401
OEM Mopar PN: 56028807AB or 5149064AB See image below

Next:
You are in the summer season, so change your oil to a diesel rated (CH4 or CK4) 15W40 or at least 10W40 or 5W40 full synthetic oil.
Only FULL SYNTHETIC Oil is recommended and if it does not have a API rating of CH4 or higher, DO NOT USE IT IN THIS ENGINE!

Recommendations: Shell Rotella T6 or Liquid Moly or Royal Purple DURALEC. All come in various weights.
Having a heavier weight (higher viscosity) oil will improve your oil pressure as it does not thin out as much when it gets hot.

rankom · **Posted:** Wed Jun 14, 2023 6:59 pm

operating engine temp idle 10 to 18 psi at 1500 rpm 40. psi. on my mechanical gauge

BC_CRDtom · **Posted:** Wed Jun 14, 2023 10:38 pm

I drained out the 0w40 T6 Rotella and filled her up with 15w40 Lucas Oil full synthetic.

No change to pressure. I drove around with the mechanical gauge hooked up through the top of my hood, and when fully warmed up I'm getting next to no oil pressure off idle, and max 20-22psi when increase rpms into the 3000+ range.

Unfortunately, I think my pressure sender is working fine :grim:

Is there anything else I'm missing?

There are no weird noises, everything seems normal outside of the low pressure.

layback40 · **Posted:** Thu Jun 15, 2023 3:11 am

Could we be seeing here a partly jammed open pressure relief valve?

WWDiesel · **Posted:** Thu Jun 15, 2023 1:33 pm

layback40 wrote:

Could we be seeing here a partly jammed open pressure relief valve?

Agree; if the oil pressure relief valve is jammed open, it could be dumping most of the oil off the pressure side of the system back into the oil pan which would greatly lower oil pressure on the complete system.
Unfortunately, to remove the engine oil pan to service the oil pressure relief valve which necessitates removal of the engine or dropping the front cradle.

FSM wrote:

The oil pressure relief valve mounts in the front of the engine block and is used to control oil flow through the engines lubrication system

BC_CRDtom · **Posted:** Thu Jun 15, 2023 1:49 pm

That’s what I was afraid of. That said, after all the recent work I’ve done slowly over the months, what’s another few weeks on jack stands? My oil pan gasket is leaking anyways.

Really wanted her up and running for the summer tho, darn, this is a big hit to the 2.8’s reliability factor imo.

Think running a detergent/flush like sea foam may do anything to free up possible gunk that may be fouling my pickup or relief valve?

WWDiesel · **Posted:** Thu Jun 15, 2023 4:07 pm

Certainly worth a try or a can of engine flush. Just don't run it too long and never under any actual load.
Another try would be to use a metal rod and place it on the side of the block where the pressure relief valve is located and rap on the end of the rod with a medium weight hammer hopefully to jar it loose if it is just simply stuck.
Another thought, if you had a bunch of gunk in your engine, your oil pickup screen could be about stopped up starving the oil pump from suction??? see drawing

BC_CRDtom · **Posted:** Fri Jun 16, 2023 10:24 am

Great diagrams, very helpful. I'll get under her today with a brass punch & hand sledge to see if I can get an angle on the pressure relief valve.

What're your guys' thoughts on using a borescope camera to try and get a visual on the oil pan pickup?

My oil has never been really dirty. Actually, ever since tuning her with GDE ECU & TCM tunes the oil has been getting progressively cleaner. While I had the intake elbow off for replacing the glow plugs, the EGR system & intake was clean. It would greatly surprise me if engine gunk is my issue.

rankom · **Posted:** Sat Jun 17, 2023 7:56 pm

make sure do not use Lucas oil stabilizer that we use on older non-emission trucks that can clog your sump pickup tube screen also do not use howes fuel conditioner (meaner cleaner) that can also clog up your injectors. the best thing is stay with standard oils like Rotella t6

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

WWDiesel wrote:

Easy fix!
Install new oil pressure switch, they can and do go bad. Had to change mine a fews years ago due to dash light coming on falsely.
AutoZone Duralast Part Number: PS401
OEM Mopar PN: 56028807AB or 5149064AB See image below

Next:
You are in the summer season, so change your oil to a diesel rated (CH4 or CK4) 15W40 or at least 10W40 or 5W40 full synthetic oil.
Only FULL SYNTHETIC Oil is recommended and if it does not have a API rating of CH4 or higher, DO NOT USE IT IN THIS ENGINE!

Recommendations: Shell Rotella T6 or Liquid Moly or Royal Purple DURALEC. All come in various weights.
Having a heavier weight (higher viscosity) oil will improve your oil pressure as it does not thin out as much when it gets hot.

Every single grade of oil you mentioned have the same viscosity at operating temperature !!!!! :5SHOTS:

BC_CRDtom · **Posted:** Fri Jun 30, 2023 11:23 pm

Well, things are not looking good. I used a borescope to inspect the inside of the oil pan, and everything looked clean. I could not get a clear look at the pickup screen, but the oil system looks clean.

Then I flushed the system with LiquiMoly, everything came out clean. I even got a brass punch and tapped it on the front passenger side of the engine block, right where it meets the oil pan and where the pressure relief bypass is located, with no luck. I did manage to chip off a piece of the engine block where it protrudes from the oil pan though, f.

The needle on the mechanical oil pressure gauge isn't hardly picking up off the bottom of the gauge when at idle warm.

I have owned this CRD for a good 5 years, and replaced the oil pressure sender sensor once already a few years ago because I was getting an oil dash light, and it didn't clear the issue. I am definitely getting little to no oil pressure now at warm idle, and its probably been this way for a long time. I have towed with this vehicle, and put a good 40k miles on it over the years an no weird noises or indications of low oil pressure. But I am clearly running low on psi.

Is the only thing left to consider is the pressure relief bypass valve being stuck open?

It is looking more and more like the pan will need to be dropped and the pickup screen & pressure relief valve inspected and serviced. Can anyone refer me to some clear instructional material on how to drop the pan?

Appreciated

WolverineFW · **Posted:** Sat Jul 01, 2023 12:37 am

Low oil pressure could be worn crankshaft bearings.

The increased gap allows the oil to leak out of its channels and not build pressure.

Sent from my SM-S906W using Tapatalk

BC_CRDtom · **Posted:** Tue Aug 01, 2023 7:58 pm

Left the jeep in the shop to collect dust for a bit. A dropping the oil pan to inspect the pressure bypass valve seems like the next logical step at this point.

Really hoping it’s not worn crankshaft bearings. I’ve serviced my oil regularly in the 5 years I’ve owned my CRD, and it’s always come out clean. Also my performance has always been good, no weird noises or smoke.

Can anyone refer me to a decent/detailed step by step to drop the oil pan? I’ve heard it’s quite involved.

WWDiesel · **Posted:** Tue Aug 01, 2023 10:40 pm

Just a thought, have you tried a different oil filter, just to rule it out.

As to R&R the oil pan, it is covered in the Factory Service Manual starting in Section 9 page 233. See link to online FSM manual below.

Quote:

2.8L COMMON RAIL DIESEL ENGINE
SECTION 9 - page 233
OIL PAN - REMOVAL
2005JeepKJServiceManual.pdf

BC_CRDtom · **Posted:** Tue Aug 01, 2023 11:31 pm

Yes, new oil filter was of the first thing I tried.

So I hope I’m misunderstanding the FSM, but in reading it, to remove the oil pan to access the pressure relief bypass I need to:

Remove the entire front end of the engine which includes the belt, fan & clutch, vibration dampener, outer timing belt cover, timing belt, inner cover, crankshaft hub (requiring a special tool), & inner engine cover…

before even starting working beneath the vehicle to begin the steps in dropping the front cradle (requiring another special tool & support lift)?…

Please tell me there is a better way. This makes no sense to me.

DieselJeepLuvr · **Posted:** Thu Aug 03, 2023 10:30 pm

BC_CRDtom wrote:

Please tell me there is a better way. This makes no sense to me.

I don't know. If it was me, I'd pull the motor, put it on a rotating engine stand, and work bottoms up.

layback40 · **Posted:** Fri Aug 04, 2023 3:00 am

DieselJeepLuvr wrote:

BC_CRDtom wrote:

Please tell me there is a better way. This makes no sense to me.

I don't know. If it was me, I'd pull the motor, put it on a rotating engine stand, and work bottoms up.

Agree with you!
If its not the relief valve, the engine must come out.

Low oil pressure - am I okay?

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