kysersolze350Z

Mines a 2008 and does the exact same thing and the dealer told me it was normal that the motor should have low oil pressure at idle to keep from causing any problems and stay around 60 normally and fluctuate as you go lower and higher in rpms 2400 rpm equals about 45'50 psi in mine...at idle warmed up mine reads about 10 and every dealer I call and talk to says its normal for that motor

Bigsyke

I just installed some krank vents, and at hot idle, I'm at 3-5psi.

The krank vents are known to drop oil pressure. Pulling vaccum from the crankcase will not push the oil into the oil pump as easily, thus the lower pressure. Either way on a vehicle with timing chains this isn't a good thing.

Check to see if you are pulling vacuum. Pull the PCV valve hose off, and try and cap the valve. Does oil pressure increase? If so, You're inlet side of the PCV system could be clogged.

I absolutely hate the oil fill/check system on the VQ. Adding a qt of oil, I saw all sorts of crap fall into the crankcase. Your oil pump takes the blow on any dirt introduced into the crankcase. Terrible design, but if your mains are fine, and you are not pulling vacuum, check the pump.

Lab-mike

Can I ask , did you ever figure out what was causing your low oil pressure? Reason I ask is I've been having the same issue. I thought it was the oil gallery gaskets on the rear timing cover and changed them. Now after changing them my oil pressure will drop after the car gets to normal warmer up temp and slowly drops to about 3-5 psi. Just wanted to see what you maybe had figured out.

john blutarski

I'm having the same issue and mine is an 08. Bumping this thread for any further information...

Markhimself876

Same issues here, 04 just hit 200k miles, oil pressure is just over 0 at hot idle with AC on or off, on very hot days here in florida the idle will go below 800 rpms (quite rough) I just changed my oil 2 days ago with royal blurple 5w-30. Should I assume blockage, or oil pump? Is this just normal for the miles I have?

Markhimself876

Just figured I should update you guys.. that engine is no more...connecting rod #6 pretty much disintegrated on my way home the other morning.

Mikeybfromnd

Bumping. 2003 manual ex, intake, wheels, lw flywheel and stage 2 clutch. 98k

Oil pressure started consistently dropping below 10 psi down to less than 5 when braking or corning very hard but usually only to the left. Once to operating temperature the effects are less noticeable.The car doesn't have a noticeable oil leak that I've been able to detect and the oil was changed about 2000 miles ago. Everything else on the car seems to be running excellently.

NissanTracker

iTrader: (8)

Bring the thread back alive... +1 here. I have a 07 Nismo and noticed that at cold start, pressure goes to about 90psi. When it warms up, the pressure is steady just below 30psi. I see the issue when I start driving and I stop at a light, the pressure drops to about 5-10 psi. I replaced the sensor and still nothing. Oil level is normal. I'm using mobile 1 5w30 full synthetic. Oil change about 500 miles ago (car sat all winter) No mods what's so ever. Car just flipped to 48k miles.
Has anyone have any other ideas? Has anyone changed the "gallery gasket"?

TeamDUZCO

Newby here, didn't want to start a new thread since I have kind of the same issue. Bought an 03 touring with 89K miles around a year ago, didn't had a functional oil pressure sensor. Regularly serviced since I bought using synthetic Mobil 1 oil and Fram XG filter.

Since my OC date was coming, I decided to adress the oil pressure sensor issue, went online and order a cheap eBay sensor (shame on me) for $15USD; today I did the oil change and placed the new sensor on without any issues. Started the car got reading on the gauge. After the car reach operational temperatura, I start noticing the OP went really low, around 5PSI, which panic me; drove it a couple miles and oil reading get around 30 - 35PSI on normal driving conditions (not passing 3K/RPM), and hardly reaching 60PSI on hard acceleration. The oil light start to came on, I assume once the car reach full operational temp.

2003 AT Touring with 105K miles, used Mobil Super Synthetic 5W20, Fram filter and cheap a$$ OPS. Any ideas?

dcains

iTrader: (15)

5w20 is not the appropriate oil for that engine, especially in your warm climate. Nissan recommends 5w30, but 0w40 would actually be better. Change the oil ASAP, and I'd also recommend not using the Fram filter. Use a Mobil 1 M1-110, which is a bit larger than the original.

TeamDUZCO

For peace of mind I'll go ahead and connect a mechanical oil pressure unit to verify the reading, hoping to get a normal reading; I assume that a way to thin oil could interfere with the psi; is the oil gonna fully leak when I disconect the OPS? Is it recommendable to fully drain it in order to do so?

dcains

iTrader: (15)

The thinner oil will lower the oil pressure. You can pull the sending unit without draining the oil, but be very careful with the threads. There have been more than a few threads here where guys have stripped the threads or cracked the upper oil pan. Since we know the incorrect oil is in the engine, the smart move is to change the oil first, and see what the result is.

The FSM states the oil pressure should be >42psi at 2500 rpms, and at normal operating temp. It may take 30 minutes or more of driving to get the oil fully warmed. At normal idle speed (~700rpm), the oil pressure should be >15psi, again at normal operating temp.

TeamDUZCO

Thanks for the reply! And yes, I kind of had a hard time to fit the sensor back in, I tought I had to put it almost all in, but when doing a little research I found you just have to put like half way in; got this crazy idea that if it went to deep something my interfere with the oil getting in the sensor, but that's only me wondering.

I definately went waaaaaay to thin in the oil, we usually when temperatures from 80 - 120 degrees, guessing the oil becomes like water once running a couple miles.

When I cold start the car it pumps 60PSI, on normal driving it goes between 25 - 35 psi but iddling at "0" - 5 psi. I'm going to change the oil and see what happens. I really find it hard to believe that the pump is failing, I've had the car for over a year wth not one single issue or weird engine noise

NissanTracker

iTrader: (8)

Did you end up going to 0w40? Did you see a difference in oil pressure? I'm about to bring it to a shop that has a good track record of the Z's... Was just curious.

NissanTracker

iTrader: (8)

Problem solved. It was the gallery gasket for sure. The top gasket was blown. Mechanic took some pictures and I'll post them tomorrow.

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 - Nissan 350Z 07-08 VQ35HR Z33
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).

Abe_Froman

I'm having this same issue. Replaced oil pressure sensor and pulled timing cover and oil gallery gasket was still intact so I am stumped. There seems to be a lot of threads on this issue but no definitive fix outside the gallery gasket. Anyone have any luck?