Low Oil Pressure at Idle

Ill · 07-14-2015, 08:32 AM

I figured since I was boosted, this would be an appropriate area to post. I also searched the forums and the information in all the threads was a bit lacking.

The past few days I have noticed that when I am warmed up and at idle, my "low oil pressure" light comes on my dash as well as my Oil Pressure gauge. I checked my oil levels, right where it is desired. I found no leaks after checking numerous times, but on a lift and looking for a puddle on the ground. When I am driving it is at roughly 60psi when I am coasting at 3k rpms, which from my understanding is normal. Car drives normal, no strange sounds or any other engine symptoms.

I plan on changing out both of the oil pressure sending units next oil change, sometime this week after I find an OEM one online to buy, I can only find ones for the z32 on z1motorsport's website, I am waiting for an email response to see if they have any for the z34.

Does anybody have any other suggestions?

jwick · 07-14-2015, 08:50 AM

First thing that came to mind for me was the sender was on the way out. Don't recall what kit you are running but I believe most of them get turbo oil feed from where the factory sender is located. Could be it got slightly damaged during install. Check the harness too and make sure it isn't damaged. Might have to resplice a wire if one got nicked.

Partsgeek.com if you just need the OEM sender.

Ill · 07-14-2015, 09:34 AM

Thanks jwick, I'll give it a look.

The weird thing is it just started up a few days ago. Not a single pressure issue for he past year.

It is super hot lately, that's when it started acting up.

DIGItonium · 07-14-2015, 10:44 AM

Oil pressure dips pretty low when it's hot out. I have an external gauge (Depo), and it can dip as low as 25 PSI range. I question the accuracy, though, since the external oil temperature gauge is off by 15F.

Ill · 07-14-2015, 11:32 AM

When I am at temp and idle, my Prosport reads 0psi or 1psi. When it was cooler out, mid 70s, it idled at around 14psi or so.

I'm sure the heat outside has a big problem with it, I am just paranoid whenever I see the warning lights at idle. When I blip the throttle in neutral both go away and act normal, so it's strictly a stand still at idle problem.

thompsontechs · 07-14-2015, 12:16 PM

Quote:

Originally Posted by Ill

When I am at temp and idle, my Prosport reads 0psi or 1psi. When it was cooler out, mid 70s, it idled at around 14psi or so.

I'm sure the heat outside has a big problem with it, I am just paranoid whenever I see the warning lights at idle. When I blip the throttle in neutral both go away and act normal, so it's strictly a stand still at idle problem.

I don't like that one bit... Mine is around 15-20 at idle and drops a bit if I drop the RPM letting the clutch out. Running 5-30 Mobile FS.

I would look hard at that, having that low of pressure, even at idle, is not good... perhaps as jwick says it's the gauge. If the pressure was really that low, you would be able to hear her knocking.

Ill · 07-14-2015, 12:40 PM

It sounds completely normal though, that's the thing that is giving me some hope. Once the stuff I ordered comes in, I'll rip it all apart and check it out, run a mechanical gauge and see if my electronic one is at fault.

jwick · 07-14-2015, 12:42 PM

Don't think I've ever checked idle in the heat. Of course I don't drive it much during the Texas summers. I usually just monitor oil temp, boost, AFR and fuel pressure.

DIGItonium · 07-14-2015, 01:03 PM

That doesn't make sense at all at 0-1 PSI with the engine idling fine. I think the lowest was 12 PSI as I get in 1st gear at low RPM. I'm sure you'll be hearing all sorts of nasty mechanical noise if oil pressure dipped that low. IIRC, isn't there a warning light on the dash for that? I don't think it's a low oil level indicator.

Cold start, my gauge shows 90 PSI. Then hovers to around 60. It'll be around 40 PSI at 3k RPM or so. That's my gauge indication, though.

Aviator44 · 07-14-2015, 02:15 PM

Had the same issue. On a hot day my oil light would come on whenever at idle. It would instantly go off once on throttle. Adjusted the tuning and raised the idle rpm. Never had an issue since.

EVOHUNTER · 07-14-2015, 06:14 PM

hook up a mechanical pressure gauge, could be a bad gauge.

We had a sentra a few days ago, oil pressure was only like 1-2 psi on the gauge.
it wouldnt pop on the oil light, we found that the oil filter came apart inside and was restricting flow.

thompsontechs · 07-15-2015, 09:31 AM

Quote:

Originally Posted by EVOHUNTER

hook up a mechanical pressure gauge, could be a bad gauge.

We had a sentra a few days ago, oil pressure was only like 1-2 psi on the gauge.
it wouldnt pop on the oil light, we found that the oil filter came apart inside and was restricting flow.

Ouch, what brand of filter?

EVOHUNTER · 07-15-2015, 11:57 AM

Quote:

Originally Posted by thompsontechs

Ouch, what brand of filter?

If I recall it was a Napa Gold line filter.

ROBERT1183 · 07-17-2015, 11:46 AM

Happens to mine too. What i noticed is that when i pulled the dipstick i heard a hissing noise as if there was too much crankcase pressure building on hot days. Im planning on running a catch can setup to help with the excess pressure in the pcv system.

Jordo! · 07-17-2015, 11:49 AM

Check sender and check any oil feed lines running to turbo...

07-14-2015, 08:32 AM	#1 (permalink)
Ill Base Member Join Date: Mar 2012 Location: Bellevue Posts: 177 Drives: 09 370z Base 6MT Rep Power: 14	Low Oil Pressure at Idle I figured since I was boosted, this would be an appropriate area to post. I also searched the forums and the information in all the threads was a bit lacking. The past few days I have noticed that when I am warmed up and at idle, my "low oil pressure" light comes on my dash as well as my Oil Pressure gauge. I checked my oil levels, right where it is desired. I found no leaks after checking numerous times, but on a lift and looking for a puddle on the ground. When I am driving it is at roughly 60psi when I am coasting at 3k rpms, which from my understanding is normal. Car drives normal, no strange sounds or any other engine symptoms. I plan on changing out both of the oil pressure sending units next oil change, sometime this week after I find an OEM one online to buy, I can only find ones for the z32 on z1motorsport's website, I am waiting for an email response to see if they have any for the z34. Does anybody have any other suggestions? __________________ Old - GTM TT Stage 1 - 487whp / 415wtrq - bunch of goodies. New - 2011 Shelby GT500 - 2.3L VMP TVS - JLT CAI.

07-14-2015, 08:50 AM	#2 (permalink)
jwick A True Z Fanatic Join Date: Dec 2010 Location: Houston Posts: 14,532 Drives: '10 G37 6MT Rep Power: 2465057	First thing that came to mind for me was the sender was on the way out. Don't recall what kit you are running but I believe most of them get turbo oil feed from where the factory sender is located. Could be it got slightly damaged during install. Check the harness too and make sure it isn't damaged. Might have to resplice a wire if one got nicked. Partsgeek.com if you just need the OEM sender. Ill likes this. __________________ '10 G37T 6MT Graphite/Graphite - BP - G37T Build

07-14-2015, 09:34 AM	#3 (permalink)
Ill Base Member Join Date: Mar 2012 Location: Bellevue Posts: 177 Drives: 09 370z Base 6MT Rep Power: 14	Thanks jwick, I'll give it a look. The weird thing is it just started up a few days ago. Not a single pressure issue for he past year. It is super hot lately, that's when it started acting up. __________________ Old - GTM TT Stage 1 - 487whp / 415wtrq - bunch of goodies. New - 2011 Shelby GT500 - 2.3L VMP TVS - JLT CAI.

07-14-2015, 10:44 AM	#4 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 43	Oil pressure dips pretty low when it's hot out. I have an external gauge (Depo), and it can dip as low as 25 PSI range. I question the accuracy, though, since the external oil temperature gauge is off by 15F. __________________

07-14-2015, 11:32 AM	#5 (permalink)
Ill Base Member Join Date: Mar 2012 Location: Bellevue Posts: 177 Drives: 09 370z Base 6MT Rep Power: 14	When I am at temp and idle, my Prosport reads 0psi or 1psi. When it was cooler out, mid 70s, it idled at around 14psi or so. I'm sure the heat outside has a big problem with it, I am just paranoid whenever I see the warning lights at idle. When I blip the throttle in neutral both go away and act normal, so it's strictly a stand still at idle problem. __________________ Old - GTM TT Stage 1 - 487whp / 415wtrq - bunch of goodies. New - 2011 Shelby GT500 - 2.3L VMP TVS - JLT CAI.

07-14-2015, 12:40 PM	#7 (permalink)
Ill Base Member Join Date: Mar 2012 Location: Bellevue Posts: 177 Drives: 09 370z Base 6MT Rep Power: 14	It sounds completely normal though, that's the thing that is giving me some hope. Once the stuff I ordered comes in, I'll rip it all apart and check it out, run a mechanical gauge and see if my electronic one is at fault. __________________ Old - GTM TT Stage 1 - 487whp / 415wtrq - bunch of goodies. New - 2011 Shelby GT500 - 2.3L VMP TVS - JLT CAI.

07-14-2015, 12:42 PM	#8 (permalink)
jwick A True Z Fanatic Join Date: Dec 2010 Location: Houston Posts: 14,532 Drives: '10 G37 6MT Rep Power: 2465057	Low Oil Pressure at Idle Don't think I've ever checked idle in the heat. Of course I don't drive it much during the Texas summers. I usually just monitor oil temp, boost, AFR and fuel pressure. __________________ '10 G37T 6MT Graphite/Graphite - BP - G37T Build

07-14-2015, 01:03 PM	#9 (permalink)
DIGItonium A True Z Fanatic Join Date: Jan 2009 Location: Kansas Posts: 3,800 Drives: 09 Z34-TT 6MT Rep Power: 43	That doesn't make sense at all at 0-1 PSI with the engine idling fine. I think the lowest was 12 PSI as I get in 1st gear at low RPM. I'm sure you'll be hearing all sorts of nasty mechanical noise if oil pressure dipped that low. IIRC, isn't there a warning light on the dash for that? I don't think it's a low oil level indicator. Cold start, my gauge shows 90 PSI. Then hovers to around 60. It'll be around 40 PSI at 3k RPM or so. That's my gauge indication, though. __________________

07-14-2015, 02:15 PM	#10 (permalink)
Aviator44 Enthusiast Member Join Date: May 2014 Location: Pensacola, FL Posts: 299 Drives: AAM Twin Turbo 370Z Rep Power: 12	Had the same issue. On a hot day my oil light would come on whenever at idle. It would instantly go off once on throttle. Adjusted the tuning and raised the idle rpm. Never had an issue since. SwedeZ likes this. __________________ www.aamcompetition.com AAM Twin Turbo System

07-14-2015, 06:14 PM	#11 (permalink)
EVOHUNTER Track Member Join Date: Jul 2011 Location: Edmonton, Canada Posts: 681 Drives: BOOSTED3-7-0 Rep Power: 16	hook up a mechanical pressure gauge, could be a bad gauge. We had a sentra a few days ago, oil pressure was only like 1-2 psi on the gauge. it wouldnt pop on the oil light, we found that the oil filter came apart inside and was restricting flow. __________________

07-17-2015, 11:46 AM	#14 (permalink)
ROBERT1183 Enthusiast Member Join Date: Feb 2013 Location: ROCKAWAY NJ Posts: 458 Drives: 2011 NISSAN 370Z Rep Power: 13	Happens to mine too. What i noticed is that when i pulled the dipstick i heard a hissing noise as if there was too much crankcase pressure building on hot days. Im planning on running a catch can setup to help with the excess pressure in the pcv system. __________________ Aam competition twin turbo 540whp @ 9psi

07-17-2015, 11:49 AM	#15 (permalink)
Jordo! A True Z Fanatic Join Date: May 2010 Location: nirvana Posts: 6,394 Drives: 2023 NATM Rep Power: 419	Check sender and check any oil feed lines running to turbo... hjo1078 likes this. __________________ Enjoy it. Destroy it.

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