Low oil pressure!

Rusty

OP, you was saying that your normal oil psi is 20 to 25 at an idle. Now it 15 psi. What is your normal operating psi and what it is now? Once you replace the sensor with a new one. If it stays the same. (I believe it will). Your first guess on the valley gaskets, would be my first guess too. Your oil pressure gauge is saving you from a major rebuild.

I have a set gaskets in my toolbox for just in case.

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TBatt

Electronic.

Your oil can have an affect on idle pressure too. Not to start another oil shootout but I run Mobile 1 0-40.

My 1977 Fiat Spider would have the oil pressure drop to the point that the oil light would flicker at idle. After installing an oil cooler on the car that problem went away.

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NissanTracker

I saw high oil pressure when i was using Mobile 1 0-40. Granted, I also have a 35 row front mount oil cooler(with a thermostat). Took forever to warm up before driving. Great for forced induction (turbos especially)

NissanTracker

..A copy a paste from the my350z forums when I had the issue


If the sensor doesn't solve your problem (usually a bad sensor just hits the rail)... then plug in a gauge and check the pressure. The gallery gaskets underneath the timing covers could be toast.

I have an HR motor and I had a similar issue. The factory gallery gaskets on the 350zHR and 370z were paper. They eventually just separate. Luckily, there is an infinity part number (now available as a nissan part number) for metal ones. In the past, you had to replace the entire timing cover. Even though the stand alone gasket is cheap, The labor is expensive.

check my posts:

https://my350z.com/forum/maintenance...st-151k-3.html



https://my350z.com/forum/vq35hr/6102...-look-for.html


pics of my bad gaskets

NissanTracker

I picked everything up at Concept Z

Here is gasket parts list:

Timing Chain Cover Seal O-Ring
Part #: 15066-JA10A $8.36 Qty: 2

Nissan OEM Rear Timing Cover Oil Gallery Gasket, Upper Large
Part #: 13533-JK21A $30.10 Qty: 1

Nissan OEM Rear Timing Cover Oil Gallery Gasket, Lower Small - VQ35HR VQ37VHR - Nissan 350Z 370Z
Part #: 13533-JK21B $4.70 Qty: 1

Nissan OEM 13042-3HD0A Intake Camshaft VTC Seal
Part #: 13042-3HD0A $34.92 Qty: 6

Nissan OEM 13510-31U10 Front Crankshaft Oil Seal
Part #: 13510-31U10 $10.74 Qty: 1

Nissan OEM VTC Variable Timing Control Solenoid Gasket RH
Part #: 23797-EY01A $4.20 Qty: 1

Nissan OEM VTC Solenoid Cover Gasket
Part #: 23797-JA10B $3.30 Qty: 1


Subtotal: $96.32
Shipping (Ground): $14.64
Total: $110.96


Extras:
Replaced all tensioners and chain guides (less than $200.00)

Labor was for 8 hours @83.00 an hour

I went a tad above 1,000 with cleanup/dispose fees, new oil + filter. 1/3rd the price from Satin (Nissan).

Spooler

It makes you wonder what mileage those gaskets go out and when did they use the updated metal ones.

NissanTracker

It depends on how you drive the car.... how often, etc... The gasket slowly starts absorbing oil and after so many pressure cycles... it's just a matter of time. The weak points seem to be where the gasket surrounds the bolts.

on my 07 Nismo, I only noticed it after someone pointed it out. I was at 40K miles. It could have started much sooner. This was 2 years ago. DE's have the same issue as well but at later miles(80k+). I believe the HR motors see it sooner... due to the high rev variant... which equates to higher oil pressure.

I was about to replace the entire timing chain cover, which was about 1,800ish alone. It was not until an Infiniti service person on my350z posted the G37 infiniti part number. CZP started carrying them and I am sure they were the "Go To" for them as well.

Anywho... i'm only giving my experience and the OP might not be experiencing this, just i know there was a lot of talk with the VQ35HR's when i was going through it.

My .02 would be get a 1/8NPT T from Homechepo, tie in an oil pressure gauge with a long line where the OE oil sending unit is and see what the actual idle pressure it. If it is low...

If I remember correctly, just pulling the small covers is enough to check. In my picture above, the full timing cover was pulled off. The gallery plate is torqued down from OEM. That gasket blew apart at that left most bolt. When the tech opened that plate up... it was in pieces, separated at each bolt.

I'm sure the pro's can also shine in

NissanTracker

@OP. And if your already in there... refer to the list I posted and replaced the guides, tensioners, etc.. I didn't replace my chain. I was told it's not necessary, but maybe someone can shine in?

Rusty

Be a good time to replace the stock oil pump with a better one.

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jmroy6

i will definitely change out the old guides/tensioners since everything will be apart anyway. I guess it would be a good idea to do an in depth DIY too.

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2012 370z GTM SC

jmroy6

Quick update:

Finally ripped the car apart today, oil galley gaskets were all intact, looks like this motor got the updated versions because they were some composite metal material instead of the old paper style. Anyway i didn't take it apart for no reason even though the gaskets didnt fail, the shitty fasteners did. On the upper galley two fastener were less than hand tight. So this is why i was getting low oil pressure drops, but no ecm codes (p0011,p0021)

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2012 370z GTM SC

Rusty

Very lucky that they didn't back all the way out and land in the timing chain.

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"The Difficult Anytime, The Impossible By Appointment Only"
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Spooler

Due to this reason right here I am going to have mine done when I get my TT install done. Might as well do exhaust cams and an oil pump upgrade too. The motor will be out, why not.

Rusty

This is on my to do list.

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浪人 - 殺し屋
"The Difficult Anytime, The Impossible By Appointment Only"
http://www.the370z.com/members-370z-...o-journal.html

NissanTracker

Looks like it was replaced and the mechanic didn't torque them down correctly?