Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Go Back   Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum > General > Tech Talk > Engine Tech

Engine Tech Technical discussion related to all relevant engines such as KA, SR, RB, CA, 2JZ , L24/26/28, VG, VQ, and LSx series.


Reply
 
Thread Tools Display Modes
Old 01-17-2020, 06:48 PM   #1
Keegster
Zilvia Member
 
Keegster's Avatar
 
Join Date: Jan 2017
Location: Charlotte
Posts: 163
Trader Rating: (0)
Keegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enough
Feedback Score: 0 reviews
SR Sr20 low oil pressure

I just rebuilt my notchtop sr20det and it has low oil pressure. I had 10w-30 in it and it turned the oil pressure light on when it was warm and idling. I switched to 15w-50 and checked it with a gauge and it was at about 8 psi warm and a little under 1000rpm. It has an s14 pick up, oem pick up gasket, and oem o ring.

It has brand new ACL race bearings I double checked the bearing clearances and it had .0008 on 2 rods and .001 on the other 2, the fsm calls for .0008 to be the tightest. The main bearings had between .001-.0012 which is a little over what the fsm wants but nothing bad especially for 15w-50.

The oil pump isn't new but had very few miles and almost now scoring on the sides and its oem pump. It had a new oem filter for a 14 or 15 sr. All 5 squirtters are there and aren't broken. One valve is out of adjustment because I lost the shim and replaced it with a random one (I found it now).

The stock t28 has an aftermarket braided line with a restrictor at the end, the line is a unknown to me because the last owner bought it. The turbo drain is a custom made one by me to correct the angle on it and it has a double silicon hose on it. The motor sports teacher at my school was thinking the oil relief valve may have been stuck, and I took it apart moves freely. He now thinks some debris could have kept the valve open because the motor sat uncovered for a while, but I've cleaned it now.

The same issue plagued the last owner of this sr20. Does anyone have any ideas of what could be giving me low oil pressure before I put it back together on Tuesday? Is there anything I missed??
Keegster is offline   Reply With Quote
Sponsored Links
Old 01-18-2020, 12:57 AM   #2
gaz_moose
Zilvia Member
 
Join Date: Mar 2008
Location: engerland
Posts: 242
Trader Rating: (0)
gaz_moose is an unknown quantity at this point
Feedback Score: 0 reviews
you could just fit a new oil pump (but not whole cover) and relief valve. to cross those off the list.
gaz_moose is offline   Reply With Quote
Old 01-18-2020, 12:24 PM   #3
anthony_240
Zilvia Junkie
 
anthony_240's Avatar
 
Join Date: Nov 2016
Location: Los Angeles
Age: 30
Posts: 489
Trader Rating: (3)
anthony_240 is an unknown quantity at this point
Feedback Score: 3 reviews
Do you have an aftermarket oil pressure gauge? Have you verified low oil pressure in the oil galleys?


Sent from my iPhone using Tapatalk
anthony_240 is offline   Reply With Quote
Old 01-18-2020, 02:47 PM   #4
S14rebuild
BANNED
 
Join Date: May 2019
Location: Florida-FAIL
Posts: 2,497
Trader Rating: (8)
S14rebuild S14rebuild S14rebuild S14rebuild S14rebuild S14rebuild S14rebuild S14rebuild S14rebuild S14rebuild S14rebuild
Feedback Score: 8 reviews
Install a mechanic oil pressure guage first and confirm the low oil pressure first!
S14rebuild is offline   Reply With Quote
Old 01-19-2020, 05:01 PM   #5
Keegster
Zilvia Member
 
Keegster's Avatar
 
Join Date: Jan 2017
Location: Charlotte
Posts: 163
Trader Rating: (0)
Keegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enough
Feedback Score: 0 reviews
Yes I checked it with a gauge, I said that in the post, a true mechanical gauge. I checked it at the original oil pressure sensor hole.
Keegster is offline   Reply With Quote
Old 01-19-2020, 05:56 PM   #6
RalliartRsX
Post Whore!
 
Join Date: Apr 2006
Location: Maryland
Posts: 4,753
Trader Rating: (32)
RalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfectionRalliartRsX is close to perfection
Feedback Score: 32 reviews
Did you install the o ring behind the oil pump?? Almost everyone I know who has taken off the oil pump always forgets the o ring. Without it, oil just bypasses the oil pump and cause the very condition you are seeing.

RalliartRsX is offline   Reply With Quote
Old 01-19-2020, 05:58 PM   #7
Keegster
Zilvia Member
 
Keegster's Avatar
 
Join Date: Jan 2017
Location: Charlotte
Posts: 163
Trader Rating: (0)
Keegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enough
Feedback Score: 0 reviews
Yes I put a brand new one on it
Keegster is offline   Reply With Quote
Old 01-19-2020, 08:53 PM   #8
s13 @ fullboost
Spirit Of Ecstasy
 
s13 @ fullboost's Avatar
 
Join Date: Dec 2007
Location: Simi Valley, CA
Posts: 2,531
Trader Rating: (15)
s13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfection
Feedback Score: 15 reviews
Send a message via AIM to s13 @ fullboost
Whats oil pressure cold? There is a good chance you have a bum pump. Do you notice any oil leaks? Pull your oil fill cap off & see if you can see your camshaft oil squirter's spraying.
__________________
s13 @ fullboost is offline   Reply With Quote
Old 01-19-2020, 09:00 PM   #9
Keegster
Zilvia Member
 
Keegster's Avatar
 
Join Date: Jan 2017
Location: Charlotte
Posts: 163
Trader Rating: (0)
Keegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enough
Feedback Score: 0 reviews
I didn't check the pressure when it was cold, but the light would stay on too long when it was started. I did check the squirters and they were just dripping, not spraying. I soaked them and made sure all the holes were clear. I forgot to mention that the oil pressure will slowly fall, I can rev it and it will go to let's say 12 psi and then it would slowly fall to about 8 psi. I find it very weird. Why would a pump that's almost new be bad?
Keegster is offline   Reply With Quote
Old 01-19-2020, 09:16 PM   #10
s13 @ fullboost
Spirit Of Ecstasy
 
s13 @ fullboost's Avatar
 
Join Date: Dec 2007
Location: Simi Valley, CA
Posts: 2,531
Trader Rating: (15)
s13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfection
Feedback Score: 15 reviews
Send a message via AIM to s13 @ fullboost
Quote:
Originally Posted by Keegster View Post
I didn't check the pressure when it was cold, but the light would stay on too long when it was started. I did check the squirters and they were just dripping, not spraying. I soaked them and made sure all the holes were clear. I forgot to mention that the oil pressure will slowly fall, I can rev it and it will go to let's say 12 psi and then it would slowly fall to about 8 psi. I find it very weird. Why would a pump that's almost new be bad?
When you rev it up whats the highest you see the oil pressure go to? Sometimes brand new parts fail right out of the box. I am trying to find the common denominator. You did a rebuild? The same oil pump was used & now you still do not have oil pressure. If you put the O-ring then its possible that the oil pump gear has flaws from the machining process. Its not able to pump, especially when the oil heats up & thins out. Possibly due to clearance issues from manufacturing?
__________________
s13 @ fullboost is offline   Reply With Quote
Old 01-19-2020, 09:57 PM   #11
Keegster
Zilvia Member
 
Keegster's Avatar
 
Join Date: Jan 2017
Location: Charlotte
Posts: 163
Trader Rating: (0)
Keegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enough
Feedback Score: 0 reviews
I have the bottom end apart to try to find the issue, and I never revved it when I had the gauge on it because I was afraid to. I can measure the pump versus a known good one before I put I back together. Nothing else comes to mind as why it could be low?
Keegster is offline   Reply With Quote
Old 01-19-2020, 10:04 PM   #12
mechanicalmoron
Zilvia FREAK!
 
Join Date: Jul 2013
Location: tx
Posts: 1,076
Trader Rating: (0)
mechanicalmoron is just really nicemechanicalmoron is just really nicemechanicalmoron is just really nicemechanicalmoron is just really nicemechanicalmoron is just really nicemechanicalmoron is just really nicemechanicalmoron is just really nicemechanicalmoron is just really nice
Feedback Score: 0 reviews
Is there an oil restrictor sandwiched between the head and block? Some cars have restrictors that manuals (and enthusiasts) don't really mention (or rather, is there a little cup in the head feed, that COULD have had a restrictor in it).



There's one google found me that says it's off a miata, I was imaging exactly that off a honda, everyone's got em.

Also, oil galley plugs leaking internally into the engine? Tensioner o-ring?

Since you mentioned it, I assume the pickup is of a different design, is it longer or does it have a different skirt design on the strainer, that's sitting on the bottom of the pan? Or is it an aftermarket pan?

I have a b18 that would sit with the light on for 30 seconds, but it didn't knock or anything so I let it ride a while - eventually I took a hammer to the dent in the pan and now she's instant.

*edit* This seems to have one

Last edited by mechanicalmoron; 01-19-2020 at 11:40 PM..
mechanicalmoron is offline   Reply With Quote
Old 01-19-2020, 10:07 PM   #13
Keegster
Zilvia Member
 
Keegster's Avatar
 
Join Date: Jan 2017
Location: Charlotte
Posts: 163
Trader Rating: (0)
Keegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enough
Feedback Score: 0 reviews
I believe that was there, I put the head on it 2 years ago. I pulled the pan off and took a hammer to it and it didn't fix the issue
Keegster is offline   Reply With Quote
Old 01-19-2020, 10:43 PM   #14
s13 @ fullboost
Spirit Of Ecstasy
 
s13 @ fullboost's Avatar
 
Join Date: Dec 2007
Location: Simi Valley, CA
Posts: 2,531
Trader Rating: (15)
s13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfection
Feedback Score: 15 reviews
Send a message via AIM to s13 @ fullboost
Quote:
Originally Posted by Keegster View Post
I just rebuilt my notchtop sr20det



The oil pump isn't new but had very few miles


The same issue plagued the last owner of this sr20
Quote:
Originally Posted by Keegster View Post
I believe that was there, I put the head on it 2 years ago.


Not trying to be a dick but I am honestly confused now?
__________________
s13 @ fullboost is offline   Reply With Quote
Old 01-19-2020, 11:51 PM   #15
Keegster
Zilvia Member
 
Keegster's Avatar
 
Join Date: Jan 2017
Location: Charlotte
Posts: 163
Trader Rating: (0)
Keegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enoughKeegster will become famous soon enough
Feedback Score: 0 reviews
I bought the motor 2 years ago disassembled. I got the rotating assembly together not long after I got it and just let it sit because I didn't need it. My ka spun a rod a few months ago and I finished the sr and put it in
Keegster is offline   Reply With Quote
Old 01-20-2020, 12:50 AM   #16
s13 @ fullboost
Spirit Of Ecstasy
 
s13 @ fullboost's Avatar
 
Join Date: Dec 2007
Location: Simi Valley, CA
Posts: 2,531
Trader Rating: (15)
s13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfections13 @ fullboost is close to perfection
Feedback Score: 15 reviews
Send a message via AIM to s13 @ fullboost
Quote:
Originally Posted by Keegster View Post
I bought the motor 2 years ago disassembled. I got the rotating assembly together not long after I got it and just let it sit because I didn't need it. My ka spun a rod a few months ago and I finished the sr and put it in
Ahhh okay now I am up to speed. Well I would carefully inspect all your oil passages. I highly suggest spending the 180 bucks & getting a new oil pump before re assembly. Just my two cents, I really hope you get it resolved. I know how frustrating things like this can be.
__________________
s13 @ fullboost is offline   Reply With Quote
Old 01-21-2020, 08:34 AM   #17
jedi03
Nissanaholic!
 
Join Date: Jul 2008
Location: albuquerque
Posts: 1,786
Trader Rating: (8)
jedi03 is on a distinguished road
Feedback Score: 8 reviews
I had same issue with my SR I rebuilt...at idle when warm was low pressure...suspected just bad gauge or sending unit, verified had good flow during idle (face full of oil with valve cover off lol) disconnected the gauge and called it good...personally had all brand new parts and had measured all parts with assembly...prob could have shimmed the pump but let us know what you find!
jedi03 is offline   Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 03:03 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
vB.Sponsors
Copyright © 1998 - 2019, Zilvia.net™