Low oil pressure at idle?

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550
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USA
Hello everyone, I am wondering if my oil pressure is lower than it should be. I installed a Glowshift oil pressure and temp gauges in my 2005 Honda Civic with a 1.7 VTEC engine (a JDM D17A) about a year ago and I was a bit concerned when I saw that my oil pressure was going down to around 12 PSI at hot idle (oil around 185 degrees). I found that the minimum spec is 10 PSI at idle with the oil at 176 degrees F and 50 PSI minimum at 3K RPM and I was exceeding both of those specs, but I still didn't like having only 12 PSI of oil pressure at idle. For those of you who are wondering, I installed the oil pressure sensor in the block where the factory switch for the idiot light was and I installed the temp sensor in my oil filter sandwich plate on my oil cooler's return side.

I was about due for an oil change at the time I installed the gauge, so I replaced my Pennzoil Platinum 5W20 with 5W30 and gained about 2 PSI at idle. It now runs at around 14 PSI at idle with the oil fully warmed up. I haven't been too worried about it since it has good pressure at normal driving RPMs (45 PSI at 2k, 65 PSI at 3K, and up to around 80 PSI at 7K redline), but I still wonder sometimes if this is something I should worry about. For what it's worth the pressure has been consistent since I installed the gauges and is not dropping over time.

The engine seems to be in very good condition inside. Before I installed it 3 years ago I planned to rebuild it to make sure everything was good, but I decided to just change the gaskets when I took it apart and found that it was very clean inside, the cylinder walls still had good crosshatching, and the 2 rod bearings I pulled looked great with only very minor scratches. Since then I have put about 30K miles on it with no problems. I did not check the oil pump while it was apart though, I assumed that it is good.

If this was your car, would you be worried about only having 14 PSI of oil pressure at idle? Thank you in advance for your input, it is much appreciated!
 

Avery4

Thread starter
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550
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What can you do about it?
If it's low enough to be a problem I could switch to the thicket oil approved by Honda (5W40), check bearing clearances and replace them if necessary, or replace the oil pump. If this is a problem I would much rather fix it now than when it spins a bearing or something else catastrophically fails.
 
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BlueOvalFitter

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If it's low enough to be a problem I could switch to the thicket oil approved by Honda (5W40), check bearing clearances and replace them if necessary, or replace the oil pump. If this is a problem I would much rather fix it now than when it spins a bearing or something else catastrophically fails.
When I used to build SBC engines, if it had low oil pressure before I rebuilt it, I put a band aid on it. Meaning, to get a little more life from it, I would install a HV oil pump and run 20W50 and/or Kendall Nitro 70 weight oil. I did this for people that came to me wanting their engine rebuilt. But, I was too busy at the time so I would band aid the engine until I could rebuild it.
 

Avery4

Thread starter
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When I used to build SBC engines, if it had low oil pressure before I rebuilt it, I put a band aid on it. Meaning, to get a little more life from it, I would install a HV oil pump and run 20W50 and/or Kendall Nitro 70 weight oil. I did this for people that came to me wanting their engine rebuilt. But, I was too busy at the time so I would band aid the engine until I could rebuild it.
I wouldn't go that thick, but I am considering switching to 0W40 or 5W40 next oil change since that is the thickest grade approved by Honda. Judging by how the engine looked inside, how it runs, how it sounds, and the fact that it doesn't burn excessive oil I don't think it's worn out, but I still don't like seeing the oil pressure going that low at idle.
 

Avery4

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IMO you are OK.
Thanks. I'm pretty much thinking the same thing since it has good oil pressure at above idle, runs great with no odd noises, and the pressure doesn't seem to be getting any lower over time, which would seem to indicate that nothing is deteriorating over time.
 
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KY, USA
Been several years since I've drove the '88 Escort I had with a mechanical gauge but, as I remember 10-15 PSI is where the warm oil pressure was at idle on it and at 50-55 MPH probably about 2K RPM warm the oil pressure was in the 40-45 PSI range. That engine had 518K miles when I quit driving it. I was running 10w40 conventional in it. I'm thinking the threshold for most oil pressure switches that turn on an idiot light is somewhere around 7-8 PSI. I'm not sure how accurate this is so take it with a grain of salt. https://findanyanswer.com/what-shou... pressure should be,that needs to be resolved.
 

BlueOvalFitter

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If that was the case I'm more than good. But 30 PSI per thousand RPM would put me significantly below the minimum spec of 50 PSI at 3K RPM.
I think your engine is just fine.
I mentioned my band aid fix for the engines that had 5 psi or less at idle, knocking, etc. Sometimes the psi was just a tad higher.
 
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2,549
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Caldwell Idaho
If it's low enough to be a problem I could switch to the thicket oil approved by Honda (5W40), check bearing clearances and replace them if necessary, or replace the oil pump. If this is a problem I would much rather fix it now than when it spins a bearing or something else catastrophically fails.
That is what is was referring to as oil would be a band aid for a worn out engine the recently replaced.
 

Avery4

Thread starter
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550
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USA
That is what is was referring to as oil would be a band aid for a worn out engine the recently replaced.
So are you implying that there is harm in switching to an oil that is recommended by Honda for my car? Honda allows the use of 0W20, 5W20, 5W30, 10W30, and 5W40, so what's the harm in switching from one recommended oil to another recommended oil if I want to?
 
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mo
I had a dodge 2.7 oil change place put 5w30. Oil lite came on at idle. Had them put required 10w30 in oil lite went off stayed off.
 

Avery4

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550
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I had a dodge 2.7 oil change place put 5w30. Oil lite came on at idle. Had them put required 10w30 in oil lite went off stayed off.
That is very interesting since 5W30 and 10W30 are roughly the same viscosity at operating temps. My guess is that they actually used 5W20 instead of 5W30
 

BlueOvalFitter

Site Donor 2021
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How do you cold start an engine with 70 when it's below 50? I tried that bandaid on an engine that had a hole somewhere and wouldn't hold water. It was hard enough to get started at 65.
I never lived in an area with temps that low, so I can't answer your question. But, I have done it where temps were in the 60's.
 
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down in the park
Hello everyone, I am wondering if my oil pressure is lower than it should be. I installed a Glowshift oil pressure and temp gauges in my 2005 Honda Civic with a 1.7 VTEC engine (a JDM D17A) about a year ago and I was a bit concerned when I saw that my oil pressure was going down to around 12 PSI at hot idle (oil around 185 degrees). I found that the minimum spec is 10 PSI at idle with the oil at 176 degrees F and 50 PSI minimum at 3K RPM and I was exceeding both of those specs, but I still didn't like having only 12 PSI of oil pressure at idle. For those of you who are wondering, I installed the oil pressure sensor in the block where the factory switch for the idiot light was and I installed the temp sensor in my oil filter sandwich plate on my oil cooler's return side.

I was about due for an oil change at the time I installed the gauge, so I replaced my Pennzoil Platinum 5W20 with 5W30 and gained about 2 PSI at idle. It now runs at around 14 PSI at idle with the oil fully warmed up. I haven't been too worried about it since it has good pressure at normal driving RPMs (45 PSI at 2k, 65 PSI at 3K, and up to around 80 PSI at 7K redline), but I still wonder sometimes if this is something I should worry about. For what it's worth the pressure has been consistent since I installed the gauges and is not dropping over time.

The engine seems to be in very good condition inside. Before I installed it 3 years ago I planned to rebuild it to make sure everything was good, but I decided to just change the gaskets when I took it apart and found that it was very clean inside, the cylinder walls still had good crosshatching, and the 2 rod bearings I pulled looked great with only very minor scratches. Since then I have put about 30K miles on it with no problems. I did not check the oil pump while it was apart though, I assumed that it is good.

If this was your car, would you be worried about only having 14 PSI of oil pressure at idle? Thank you in advance for your input, it is much appreciated!

No I wouldn't be worried. My car in fact regulates oil pressure to 15 psi most of the time. Variable displacement oil pump...
 

Avery4

Thread starter
Messages
550
Location
USA
Since I installed my oil cooler before I installed the gauge I wanted to eliminate it as a possible cause for the low pressure at idle, so I unscrewed the sandwich plate and screwed the filter directly onto the block to see if eliminating the cooler would increase the pressure and it did not. I didn't think it was the problem since the pressure at higher RPMs is good and I would think a restriction would show more at a higher RPM when the pump is pushing a lot of oil through the system, but the only way to be sure is to test it.

Another possibility I thought of is that my gauge may not be accurate at lower pressures. It seems odd that at ~750 RPM idle I get 14 PSI and slightly raising the RPM to around 1K or so dramatically raises the pressure to around 27 PSI, I would expect a more linear increase. Does it make sense that a 25% increase in RPM nearly doubles the pressure?
 
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