Oil PSI

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Bigskyroadglide

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Question for you, 16 Ram Larmine sport,, 4x4 5.7, 8 speed, 3.21 gears. 65k miles, only mod is a catch can.

Running 5w30 redline and Rp 20 820 filter, less than 1500 miles on oil change.

Here is issue, at speed oil psi 53, at cold idle 58 psi (start up) at warm idle 48 psi.

Oil PSI after 2 hours of driving, upon stopping 39 to 41. Cut off truck immediately restart oil psi 48?

I'm thinking oil sending unit, or pcv valve.

Truck has been on redline since 10k, steady diet of srt filters or rp 20 820,

Never had this issue before. Fuel mileage 18 mpg on real gas.

This just happened driving from Montana to Minnesota. Avg temp, 10. degrees, -2 start up to 22 stop.

Thoughts? no startup knock, no noises, Truck performed flawlessly.

Appreciate any thoughts
 

JHoward

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Question for you, 16 Ram Larmine sport,, 4x4 5.7, 8 speed, 3.21 gears. 65k miles, only mod is a catch can.

Running 5w30 redline and Rp 20 820 filter, less than 1500 miles on oil change.

Here is issue, at speed oil psi 53, at cold idle 58 psi (start up) at warm idle 48 psi.

Oil PSI after 2 hours of driving, upon stopping 39 to 41. Cut off truck immediately restart oil psi 48?

I'm thinking oil sending unit, or pcv valve.

Truck has been on redline since 10k, steady diet of srt filters or rp 20 820,

Never had this issue before. Fuel mileage 18 mpg on real gas.

This just happened driving from Montana to Minnesota. Avg temp, 10. degrees, -2 start up to 22 stop.

Thoughts? no startup knock, no noises, Truck performed flawlessly.

Appreciate any thoughts

My 2017 HEMI is identical to your oil psi's.

Same oil with the exception of currently running the AMSOIL EAO11. I had the same psi at start up/drive/hot idle, etc. when I was using the Royal Purple 20-820.

Imo, I reside in Louisiana where the temperature is much warmer than where you are, however with the "artic blast" we had a few days ago made a little difference in psi running up a smidgen.

My HEMI is doing good. I already have replaced the PVC @36,000 miles and currently have 45,000.

Hope that helped.
 
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I've got Valvoline 5w20 in mine right now, and that's about the same pressure I get in similar temps. Is your oil temp higher than expected? Turning it off and back on could be recalibrating the sensor, or because it revs as it starts it's building pressure back up.
 

crazykid1994

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What is your oil temp. Higher oil temp will also read lower oil pressure. My usual oil pressure hot idle was 41 psi around 199° oil temp. Once oil temp got above 203° my idle oil pressure would drop to 38psi. After bumping my idle rpm up to 650rpm my idle oil pressure stays around 41psi up to 203° oil temp. How many miles since your last oil change and what oil and filter did you use? I have a filter relocation kit on the truck so my oil usually doesn’t go above 203° anymore and I run a larger filter than what was stock on my 2017
 
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Bigskyroadglide

Bigskyroadglide

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Idle is stock, as stated no mods on this truck. Oil temp is 213 to 215. Has stock 203 thermostat for engine coolant. Coolant temp is 203. Trans temp is 185.

It has fresh redline 5w30 less than 1500 miles ago with a rp 20 820 filter.

The concern for me is this truck at warm idle no matter temp, speed or miles traveled has never had a warm idle oil psi less. Than 48. Now it's suddenly 41, cut it off restart it. It jumps back to 48.

It mimics a bad sending unit for oil psi. Just not willing to change it out if I'm not sure. Mechanically the truck is running perfectly
 

Sherman Bird

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Question for you, 16 Ram Larmine sport,, 4x4 5.7, 8 speed, 3.21 gears. 65k miles, only mod is a catch can.

Running 5w30 redline and Rp 20 820 filter, less than 1500 miles on oil change.

Here is issue, at speed oil psi 53, at cold idle 58 psi (start up) at warm idle 48 psi.

Oil PSI after 2 hours of driving, upon stopping 39 to 41. Cut off truck immediately restart oil psi 48?

I'm thinking oil sending unit, or pcv valve.

Truck has been on redline since 10k, steady diet of srt filters or rp 20 820,

Never had this issue before. Fuel mileage 18 mpg on real gas.

This just happened driving from Montana to Minnesota. Avg temp, 10. degrees, -2 start up to 22 stop.

Thoughts? no startup knock, no noises, Truck performed flawlessly.

Appreciate any thoughts
It ain't broken, and you're worried?
 

Burla

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If there is an issue it is most likely with fuel/air and not oil or spark. But I don't think there is an issue, keep an eye on it if it gets gets worse then report back. If there is an issue it would get worse. Clean/Check the throttle body and check air filter, run some redline si-1 through injectors. Next time I am out I will record my numbers doing what you did just for comparison. You need to know what the starting minimum guage reading is, maybe it is 48. You need to test psi from engine and not trust a gauge.
 

jws123

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Whats with all the paranoid threads lately with oil PSI like mentioned above the guage in truck is not all that accurate your numbers sound normal I get 23 PSI hot idle so your doing dam good!.
 
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Bigskyroadglide

Bigskyroadglide

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Thanks for the feedback, sound advice to verify via a mechanical gauge.

Super cold temperatures bring out odd potential problems. Curious to others experience, only.

Thanks
 

turkeybird56

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If there is an issue it is most likely with fuel/air and not oil or spark. But I don't think there is an issue, keep an eye on it if it gets gets worse then report back. If there is an issue it would get worse. Clean/Check the throttle body and check air filter, run some redline si-1 through injectors. Next time I am out I will record my numbers doing what you did just for comparison. You need to know what the starting minimum guage reading is, maybe it is 48. You need to test psi from engine and not trust a gauge.
His PSI numbers are exactly what MY 19 numbers are, on 5W20 PUP oil and Fram Filter.
 

Burn2k12Ram

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Keep a close eye on your idle. Sounds like maybe it is dropping below that 650 and accounts for that small amount of psi drop when warm. Restarting truck obviously fixes for time being.
 

Burla

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@Bigskyroadglide can you post the rpm at each psi reading you are concerned about, the only real way to tell without using a gauge directly on the oil sensor.
 
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Bigskyroadglide

Bigskyroadglide

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@Bigskyroadglide can you post the rpm at each psi reading you are concerned about, the only real way to tell without using a gauge directly on the oil sensor.
Thanks Burla,

I'm driving back from Minnesota to Montana on Saturday so will see if similar experience, with oil psi. If so, I have a heated garage and a manual gauge to check out the issue. I suspect it is the sending unit if anything. Doubtful it's a major issue. If sending unit, quick trip to MA Mopar will fix. I've already called my local dealership and they have the OEM part in stock if needed.

Driving 1100 miles in -26 weather has the tendency to find the weak link in boardline parts. This maybe the result.

Answers to your questions

Cold Idle 1000. 55 to 58
warm idle 550 rpm 48
1800 to 2k rpm. 53
Warm idle 550, oil temp 213 , after 2 hour drive 41
Warm start 48

I'll take more specific readings on Saturday, course it will be 30 degrees

Thanks
 

Burla

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If you remember put that gauge on after a long drive, for sure something is a miss if two warm rpm's 550 are showing different psi by 7. Could be gauge or maybe that sensor, or something else we are missing.
 
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Bigskyroadglide

Bigskyroadglide

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@Burla, here are drive back photos, warmer the outside temp, higher the pressure.

Manual gauge review tomorrow when the world reopens
 

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Wild one

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@Burla, here are drive back photos, warmer the outside temp, higher the pressure.

Manual gauge review tomorrow when the world reopens
The sending unit on my 14 went south when the truck had about 13,000 miles on it and was only about 2 years old.At the time,the new unit was supposedly an updated sender,all i know is the new sender has never gave me any static since. My pressures would vary from about 10 psi all the way to 99 psi,while the truck was idling
 

ThunderMug95

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The last sending unit I had go bad was on a ‘96 ZJ I was messing around with…It let go on the highway and oiled EVERYTHING on the Jeep nicely! Luckily I came to a stop in front of an Advance Auto and I replaced the sender/oil on the shoulder…Out of curiosity, wheres the unit on the 5.7?
 

crazykid1994

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The last sending unit I had go bad was on a ‘96 ZJ I was messing around with…It let go on the highway and oiled EVERYTHING on the Jeep nicely! Luckily I came to a stop in front of an Advance Auto and I replaced the sender/oil on the shoulder…Out of curiosity, wheres the unit on the 5.7?
Right above the oil filter. I’m actually curious what the other sensor pictured is though.
 

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