2014 hemi 5.7, gradual loss of oil pressure

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ArfDogZYX

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Hello - trying to get a sense of what I might be in for here. all numbers are engine warm.

200k miles 2014 5.7 hemi; using synth 5/20. in recent months at 1500 rpm oil psi has been around 53 (in months prior, was closer to 57). idle would be around 43.

friday noticed it was at 47psi at 1500 rpm, consistent the rest of the day (kept it on dash). Saturday started and ended at 45 at 1500 rpm - had dropped 2 but did not drop during the day more. sunday, 20 degrees warmer outside, at 44 psi, and idle is now down to 38-39psi. have not cranked today yet but will get to that in a bit. shop won't see it until wednesday. truck gets about 200 miles a day, city/highway mixed.

last oil change 4500 miles ago - same garage has done all mechanical and oil changes on it last 60k miles.

what might I be looking at? the gradual psi reduction, almost like clockwork overnight, may suggest possible culprits (I hope).
 

jws123

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Switch to 5w30 on my 2011 with 230k my hot idle oil pressure is 22-25 psi fathers 2500 sits around 30psi been running like this for years your numbers are normal. At a minimum if it bothers you and you think there is a issue get the oil and filter changed could be a filter issue.
 

Daw14

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Might be a filter issue as there have been reports on here of bad/defective ones . Maybe your oil pressure sending unit is going bad. I run a mechanical gauge after my original sending unit died with under 10,000 miles on it , no more worries if the pressure is accurate or not.
 

CamperMike

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How long since you changed the oil? I noticed reduced oil pressure a few thousand miles after I bought the truck from a Ford dealer. The first oil change they were back up. Not sure if the oil or the filter was the issue but I would definitely change your oil and filter to see if that helps. Whatever oil and filter my ram dealer uses does not seem to have the problem.
 

Tom6363

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Your symptoms mirror those on my 6.4. Dealer found shavings in the oil pan and the rest is history....$12K for a replacement. No loss of power, no strange noises, NO symptoms but oil pressure slowly dropping to 28 on the hiway. The dealer would tear the engine down for $4K and let me know what happened...I declined that offer. 3yr/100k warranty and then I'm selling the damn thing. It's been babied its whole life and let me down. The engine was one of the 6.4's that were built with the wrong wristpin, 125k miles and this is the 3rd engine installed, and my mileage has decreased and it doesn't feel like it has the same power.
 
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ArfDogZYX

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Might be a filter issue as there have been reports on here of bad/defective ones . Maybe your oil pressure sending unit is going bad. I run a mechanical gauge after my original sending unit died with under 10,000 miles on it , no more worries if the pressure is accurate or not.
pressure went back to the low 40s idle/53psi at 1500 rpm instantly after oil change.

2000 miles later, dropped very quickly one afternoon to low 30s idle, high 30's 1500rpm. higher a few minutes afte warm cranking after it has set a few (less than 5) moments. (still quite warm). still there, looking at what to do with it today.
 
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ArfDogZYX

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How long since you changed the oil? I noticed reduced oil pressure a few thousand miles after I bought the truck from a Ford dealer. The first oil change they were back up. Not sure if the oil or the filter was the issue but I would definitely change your oil and filter to see if that helps. Whatever oil and filter my ram dealer uses does not seem to have the problem.
hi, the filter/oil change put it back to normal for 2000 miles, now even lower than before (dropped very quickly over an hour or two of driving at that point, low 30's idle, high 30's at 1500rpm. garage surely used identical filter to what they always use. debating on next step. change filter again and see if replicates?
 

EdGs

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I would check it with a mechanical gauge, don't know if it's possible to use a tee and still have the oil pressure sender still connected.

That would tell you right there, you could see if the pressure readings match.

Sending units do go bad.
 

Daw14

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I would check it with a mechanical gauge, don't know if it's possible to use a tee and still have the oil pressure sender still connected.

That would tell you right there, you could see if the pressure readings match.

Sending units do go bad.
It is possible to use a tee as that is just what I did 8 + years ago , get some AN fittings and line drill a hole through the clutch firewall block off , there are gauge mounts for over the steering wheel or on the a pillar.
 

EdGs

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I have a bad sending unit on my 02 1500. I put 3 aftermarket sensors in and None of them worked for very long.

The current one stays on zero almost forever, then it will read, then ding and drop to zero.

I've been procrastinating on buying an OE sender, and have hooked a gauge up and verified pressure.

If it was really zero, it would make itself known very quickly, IMO
 

Daw14

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I have a bad sending unit on my 02 1500. I put 3 aftermarket sensors in and None of them worked for very long.

The current one stays on zero almost forever, then it will read, then ding and drop to zero.

I've been procrastinating on buying an OE sender, and have hooked a gauge up and verified pressure.

If it was really zero, it would make itself known very quickly, IMO
any sensor should be OEM,aftermarkets cause issues, and lots of times multiple changes till a satisfactory one Is found .
 

EdGs

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any sensor should be OEM,aftermarkets cause issues, and lots of times multiple changes till a satisfactory one Is found .
Yep, a hard lesson learned.

With the oil pressure switch on my '02, I tried 2 different makers. The first one would not read right out of the box, got a 2nd one, it lasted a month. Got one from different mfr, it lasted a few months, and here we are.

OE for me, even though it hurts.
 

DtheBC

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I had the same issue back in early spring and a filter fixed my pressure. I opened the filter and couldnt find anything amiss. But it had to have been broken in some way. It could be the filters they are using are defective or media that clogs quickly.
 

Burn2k12Ram

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My thought is if it was good for 2000 miles then dropped again your filter clogged or bad again. Could have something internal clogging that filter sooner than later. Time for a UOA.
 

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