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Acura EL
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Discussion Starter · #1 ·
so not long ago, i started to notice the oil pressure in my car starting to drop to rather low levels.. this was around a month after the motor was freshly built and had a ported oil pump with 20w-50.

it was around 12psi hot idle
40-42 psi at 3k rpm
64 psi at 5k rpm

i showed this to my tuner and we both agreed it would be a good idea to check the bearings, this is what we found.
138862



138863
138864
138865


so after viewing this, the crank was changed along with bearings that have more clearance (hx i believe). he shimmed the pump aswell this time around.

here's the problem now, we're still getting the same oil pressure as before even with a new crank, bearings, and a shimmed pump...

any suggestions??
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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Build a clean room to assemble your engine in, scrub oil passages out with bore brushes, have the machine shop chamfer the crank oiling holes and micro polish the journals and bearings, or just pay a machine shop to do a full long block for you. And run oil that matches your clearance, on a fresh rebuild with tight end of the spec clearance at 80°f ambient temps you need 5w30 for a y3,y5,y7,y8 as ambient temp goes up so does oil wieght, it also goes up as clearances wear in, you can't shove 20w50 though clearance for 5w30 at any pressure, thereby starving the crank journals for fresh oil.
 

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Discussion Starter · #3 ·
Build a clean room to assemble your engine in, scrub oil passages out with bore brushes, have the machine shop chamfer the crank oiling holes and micro polish the journals and bearings, or just pay a machine shop to do a full long block for you. And run oil that matches your clearance, on a fresh rebuild with tight end of the spec clearance at 80°f ambient temps you need 5w30 for a y3,y5,y7,y8 as ambient temp goes up so does oil wieght, it also goes up as clearances wear in, you can't shove 20w50 though clearance for 5w30 at any pressure, thereby starving the crank journals for fresh oil.
well im assuming that was all done and yes the clearances were made for 20w-50, and that's exactly what I did the first time; paid a machine shop to do the full long block since the block is sleeved as well.

we're all here scratching our heads over this. im thinking maybe a tired oil pump? a bad gauge? I have no idea.
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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Those bearings look heat blued to me, or is that the lighting? Did you use 20w50 durring break in? What was your break in procedure? Who ported the pump? Does the main girdle hold pressue? I've seen galley plug and/or sealing washer cause oil starvation, if its been notched for clearance ive seen some present with cracks in the galley as well.
 

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Discussion Starter · #5 ·
Those bearings look heat blued to me, or is that the lighting? Did you use 20w50 durring break in? What was your break in procedure? Who ported the pump? Does the main girdle hold pressue? I've seen galley plug and/or sealing washer cause oil starvation, if its been notched for clearance ive seen some present with cracks in the galley as well.
its the coating on top of the bearings, the only one that was "toast" was #4, the rest were actually alright. yes I used 20w-50 for the break in.

started the motor, changed the oil.
drove around a bit, changed the oil.
drove 500km of normal driving, changed the oil.
how do I test if the girdle holds pressure?
the shop I brought it to did the porting of the pump as well as the shimming
 

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The times I've found them cracked it was apparent after a closer inspection, the sealing washer and galley plug were harder to find, I had to pull the pressure sender and pressurize with air from there.
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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It could have been some trash in an oil passage that got missed, a minor miscalculation on clearances, a tiny bur in the rod bolt threads, an imbalance on the flywheel or clutch. What do the mains look like? Any irregular wear on 4 and 5?
 

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Discussion Starter · #9 ·
It could have been some trash in an oil passage that got missed, a minor miscalculation on clearances, a tiny bur in the rod bolt threads, an imbalance on the flywheel or clutch. What do the mains look like? Any irregular wear on 4 and 5?
It’s on a different crank right now, and the mains were in perfect condition but I haven’t taken apart the motor yet for a second time. I’m still driving it around here and there on this pressure.

The pictures of the bearings are the bearings that were previously in the car when the issue first started
 

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I'd consider upgrading the oil pump, could be it just cant flow enough 20w50 to maintain pressure on the #4 journal. Have you tried playing with the wieght? Try stepping down to 10w40 and see what happens, I often see people running a heavy wieght oil that dont necessarily need it, loose end of spec on a y5 maximum oil wieght needed at 95°F ambient temp is 10w40, running anything thicker could be bottle necking it in the galley.
 

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Discussion Starter · #11 ·
I'd consider upgrading the oil pump, could be it just cant flow enough 20w50 to maintain pressure on the #4 journal. Have you tried playing with the wieght? Try stepping down to 10w40 and see what happens, I often see people running a heavy wieght oil that dont necessarily need it, loose end of spec on a y5 maximum oil wieght needed at 95°F ambient temp is 10w40, running anything thicker could be bottle necking it in the galley.
I would completely agree with you about stepping down the oil however when the motor was first put together it had proper oil pressure, which tells me that something’s worn now and it has nothing to do with the crank or bearings since they just got changed 🤦‍♂️

I actually ordered a pump from badguys and I’m supposed to receive it in a month or so. There’s nothing else that comes to my mind that would cause this
 

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I've heard that wait time on bad guys pumps goes down considerably if you ship them a new oem pump, id say after install try 10w40 and see where the pressure is, it may actually be the 20w50 wearing the pump spring out, something I've seen on small block chevy and ford's running high volume/pressure pumps but not on Hondas specifically.
 

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I would completely agree with you about stepping down the oil however when the motor was first put together it had proper oil pressure, which tells me that something’s worn now and it has nothing to do with the crank or bearings since they just got changed 🤦‍♂️

I actually ordered a pump from badguys and I’m supposed to receive it in a month or so. There’s nothing else that comes to my mind that would cause this
What are your actual bearing clearances?

What kinds of bearings are you running?
 

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Discussion Starter · #14 ·
I've heard that wait time on bad guys pumps goes down considerably if you ship them a new oem pump, id say after install try 10w40 and see where the pressure is, it may actually be the 20w50 wearing the pump spring out, something I've seen on small block chevy and ford's running high volume/pressure pumps but not on Hondas specifically.
the only other thing I can maybe contribute this too is if the motor is just running too hot or maybe there's a pressure bleed somewhere with my vtec.. or just simply a worn out pump. im taking everything you're saying into consideration but I just dont believe it can be a blocked passage or something wrong with the block itself since it was just sent out to get sleeved and like mentioned before, ran perfectly fine for the first couple months of having it on the road.. im really stumped with this one.

I will try a different weight oil however. right now im using castrol 20w-50. im sure if I mentioned the brand before either..
 

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You cannot run 20w50 if bearing clearances and oil pump health are not suited to run 20w50.

Oil pressure is not the only thing that keeps bearings alive, it can be argued that oil volume is just as, if not more important, but the two need to work together. Oil pressure just means your pump is trying to shove oil past a restriction. Oil volume is how much oil overall can be moved through the restriction. Remember, your oil pressure measurement is in a galley far away from the bearings.

Honestly, your oil pressure readings are a bit low in the higher RPM (3K and up areas), but hot idle at 12ish psi is pretty normal.

What this means is that the oil pump could be having a hard time moving the oil through the pump and through the engine itself.

The last time my engine ran on 5w30 without an oil cooler, i had the following pressures with a pretty used oil pump:

Hot oil, hot ambient air temp (95°F+)
-12PSI idle
-50PSI cruise (2500-3000 rpm)
-80PSI+ above 5000rpm

That's with 5w30 oil and bearing clearances about midway in the spec.

If you are running OE clearances, you should NOT be running 20w50. That poor engine will be starving for oil when cold with 20 weight viscosity, and cannot move the volume needed through stock clearances with a 50 weight viscosity once at temp.

At most with stock clearances, you should run a good quality 10w30.

Read this for more info:

 

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In case that article isn't read, here is the rule of thumb chart on bearing clearances and oil viscosity:

Main Bearing ClearanceOil Temp Less
than 160 F
Oil Temp
160-220F
Oil Temp
Over 220 F
Iron Block
0.0034-0.003910w40 or 15w4015w50-20w5020w60 – 60w
0.0028-0.00335w30 or 10w3010w40 or 15w4015w50-20w50
0.0022-0.0027 0w20 or 5w205w30 or 10w3010w40 or 15w40
0.0016-0.0021 0w10 0w20 or 5w205w30 or 10w30
0.0010-0.0015 0w5 0w10 0w20 or 5w20
Aluminum Block
0.0029-0.003410w40 or 5w4015w50 or 20w5020w60 or 60w
0.0023-0.00285w30 or 10w3010w40 or 15w4015w50 or 20w50
0.0018-0.0022 0w20 or 5w205w30 or 10w3010w40 or 15w40
0.0012-0.0017 0w100w20 or 5w205w30 or 10w30
0.0006-0.0011 0w50w100w20 or 5w20
Connecting Rod Clearance

ClearanceOil Temp Less
than 160 F
Oil Temp
160-220F
Oil Temp
Over 220 F
Steel Rod
0.0028-0.00335w30 or 10w3010w40 or 15w4015w50 or 20w50
0.0022-0.00270w20 or 5w205w30 or 10w3010w40 or 15w40
0.0016-0.00210w100w20 or 5w205w30 or 10w30
0.0010-0.0015Ow50w100w20 or 5w20
Aluminum Rod
0.0023-0.00285w30 or 10w3015w50 or 20w5020w60 or 60w
0.0018-0.00220w20 or 5w2010w40 or 15w4015w50 or 20w50
0.0012-0.00170w105w30 or 10w3010w40 or 15w40

*When there is a conflict between rod and main clearances, it’s always best to use the heavier of the two viscosity recommendations.


It’s important to choose the correct viscosity grade for the maximum engine oil temperature. As oil temperatures increases, the viscosity will drop.

Unless you're balls to the walls on the track generating fuck tons of heat, with bearing clearances as loose as a $5 hooker, do not run 20w50!!!
 

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Discussion Starter · #18 ·
In case that article isn't read, here is the rule of thumb chart on bearing clearances and oil viscosity:

Main Bearing ClearanceOil Temp Less
than 160 F
Oil Temp
160-220F
Oil Temp
Over 220 F
Iron Block
0.0034-0.003910w40 or 15w4015w50-20w5020w60 – 60w
0.0028-0.00335w30 or 10w3010w40 or 15w4015w50-20w50
0.0022-0.0027 0w20 or 5w205w30 or 10w3010w40 or 15w40
0.0016-0.0021 0w10 0w20 or 5w205w30 or 10w30
0.0010-0.0015 0w5 0w10 0w20 or 5w20
Aluminum Block
0.0029-0.003410w40 or 5w4015w50 or 20w5020w60 or 60w
0.0023-0.00285w30 or 10w3010w40 or 15w4015w50 or 20w50
0.0018-0.0022 0w20 or 5w205w30 or 10w3010w40 or 15w40
0.0012-0.0017 0w100w20 or 5w205w30 or 10w30
0.0006-0.0011 0w50w100w20 or 5w20
Connecting Rod Clearance

ClearanceOil Temp Less
than 160 F
Oil Temp
160-220F
Oil Temp
Over 220 F
Steel Rod
0.0028-0.00335w30 or 10w3010w40 or 15w4015w50 or 20w50
0.0022-0.00270w20 or 5w205w30 or 10w3010w40 or 15w40
0.0016-0.00210w100w20 or 5w205w30 or 10w30
0.0010-0.0015Ow50w100w20 or 5w20
Aluminum Rod
0.0023-0.00285w30 or 10w3015w50 or 20w5020w60 or 60w
0.0018-0.00220w20 or 5w2010w40 or 15w4015w50 or 20w50
0.0012-0.00170w105w30 or 10w3010w40 or 15w40

*When there is a conflict between rod and main clearances, it’s always best to use the heavier of the two viscosity recommendations.


It’s important to choose the correct viscosity grade for the maximum engine oil temperature. As oil temperatures increases, the viscosity will drop.

Unless you're balls to the walls on the track generating fuck tons of heat, with bearing clearances as loose as a $5 hooker, do not run 20w50!!!
 

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Discussion Starter · #19 · (Edited)
You cannot run 20w50 if bearing clearances and oil pump health are not suited to run 20w50.

Oil pressure is not the only thing that keeps bearings alive, it can be argued that oil volume is just as, if not more important, but the two need to work together. Oil pressure just means your pump is trying to shove oil past a restriction. Oil volume is how much oil overall can be moved through the restriction. Remember, your oil pressure measurement is in a galley far away from the bearings.

Honestly, your oil pressure readings are a bit low in the higher RPM (3K and up areas), but hot idle at 12ish psi is pretty normal.

What this means is that the oil pump could be having a hard time moving the oil through the pump and through the engine itself.

The last time my engine ran on 5w30 without an oil cooler, i had the following pressures with a pretty used oil pump:

Hot oil, hot ambient air temp (95°F+)
-12PSI idle
-50PSI cruise (2500-3000 rpm)
-80PSI+ above 5000rpm

That's with 5w30 oil and bearing clearances about midway in the spec.

If you are running OE clearances, you should NOT be running 20w50. That poor engine will be starving for oil when cold with 20 weight viscosity, and cannot move the volume needed through stock clearances with a 50 weight viscosity once at temp.

At most with stock clearances, you should run a good quality 10w30.

Read this for more info:

ya this sounds a bit more like the case.. I guess well find out when I get the pump but yes the clearances in the motor are definitely for 20w-50.

ya im not really too concerned with what it idles at either, but ya the higher rpm's start to look a bit scary. what else could cause a loss of oil pressure over the course of 2-3 months other than a pump??
 

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Discussion Starter · #20 ·
As for the clearances, I’ll have to ask the machine shop but im running hx bearings
 
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