Tom B517

Hello everyone! Kind of new to the Z community! Picked up my first 350 a month or so ago. She's got 98K on it. Just yesterday I experienced an issue. The oil light flashed once at me taking a turn onto a street on my way to work. Today, in the same gear, same turn, and same speed it happened again. I have been unable to replicate it beyond those two instances. Does anyone have any insight on this? Also what is considered normal for oil PSI? I could never get it above 40-50 before I did the oil change. After it would hover around 40 and go up to about 80-90 on WOT. I also changed my oil less than 500 miles ago with Castrol Full Synthetic. Now it won't go above 50 on WOT. Any/all feedback and help is appreciated! Thanks!

terrasmak

iTrader: (8)

Have you used the dipstick? I would start there for for now, and btw you never seemed to mention oil weight

Tom B517

I changed it with 5w30 and the dipstick shows oil level OK although from what I'm reading the dipstick is extremely inaccurate.

terrasmak

iTrader: (8)

Dipstick is highly accurate, just hard to get a good reading. Common oil light problem is you burn oil and starve it under hard cornering.

icer5160

iTrader: (4)

Could be the oil galley gasket inside the timing case. What year is your Z? (As a side note; always indicate the year, trim package, and mileage of your Z to help narrow down possible causes) This problem has only been reported on VQ35HR and VQ37HR equipped Zs/Gs. Symptoms will include low oil pressure readings at idle (warm or cold) and codes P0011/P0021. There's an updated replacement gasket to replace the OEM paper gasket:

https://www.z1motorsports.com/front-...et-p-8880.html

This repair should not be attempted by the inexperienced. Take it to a shop with Z/G experience if you're not sure how to diagnose or execute the repair.
Good Luck!
-Icer

Tom B517

Mine is an 06 touring with just under 100K. Sadly no HR for me!

icer5160

iTrader: (4)

Since you have an 06, I suspect the pressure sensor sending unit is acting up (not terribly uncommon) or a wiring fault (perhaps a loose or corroded connection to sending unit). As Terrasmak mentioned, start with dipstick readings (car on level ground after letting it sit for at least 30 min for a more accurate reading).

Normal oil pressure readings should be near as follows:
Cold Start idle: ~ 85 - 90psi (this can easily go higher as the engine can idle near 3k RPM upon initial cold start and quickly drop)
Operating Temp idle: ~ 25-30psi

Readings will vary slightly depending on oil viscosity and fill level.

Good Luck!
-Icer

Tom B517

My pressure gauge sits at about 30-32 PSI at all times. Cold or warm, light gas or WOT. When I first changed the oil about 300 miles ago it would idle like you said, about 80-85.

icer5160

iTrader: (4)

Yeah, I would locate the sending unit and simply unplug it to see if you get a change in the needle. That will help confirm if the issue is the sending unit vs. the needle gauge itself. It's very rare for the gauge stepper motors to have issues in 350Zs, so I suspect the sending unit is bad.
-Icer

terrasmak

iTrader: (8)

Is the car a stick or auto ?

Tom B517

Manual transmission

Tom B517

UPDATE: Did an oil change today, roughly 400 miles and 3 weeks after my initial oil change right after I bought it. I'm embarrassed to say the motor only had 1.3 quarts in it. Filled it with the full 5 quarts on my last oil change. No spots on the ground after sitting for a few days. So I lost 3.7 quarts in 3 weeks and nice easy driving, So it looks like it's engine rebuild time!

NissanTracker

iTrader: (8)

Dang! I'm in Mass as well. Have a 07 Nismo. I had the Oil gallery gasket issue and never saw those symptoms. I had low oil pressure and I was lucky to catch it in time. I noticed lifter tick (had an old 97 Eclipse GS-T that had the same issue by factory... so I picked it up quickly).
If your going through oil like that, you should be seeing smoke out of the exhaust. Maybe check for oil leaks at the oil pan? Maybe bottomed out or something.

**EDIT** you clearly said no spots on the ground.

On a cold start, what are you seeing for oil pressure? I'm running mobile 1 0w40 (i'm supercharged, so I stick with this) and I see 120psi for oil pressure at startup. When I was running 5w30, it was still close to that.

Where in mass?

icer5160

iTrader: (4)

Sounds like you have the dreaded Revup DE oil consumption issue. Yours is an extreme case. My 06 got up to burning 3 quarts between changes, about a quart per 1k miles which was still manageable, but nearly 4qts in just 400 miles is nutty. Yep, it's new engine or rebuild time.
Good Luck!
-Icer

terrasmak

iTrader: (8)

yup, exactly what I was thinking

THIRZTY

Damn... Welcome to the 'previous owner didn't disclose this car is an oil consuming pos' club Been there... now mine is built.

travlee

iTrader: (8)

i dont know about yall... but every time i buy a used car, an oil change is one of the first things i do...usually within a couple of days

Tom B517

I live in Granby. About 10 minutes to Springfield. After the oil change yesterday I'm seeing cold idle around 70-80. And yes when I first got it anytime I revved it, black smoke would come out. Ran a couple fuel cleaners and now it's only blows a little bit of white smoke. However after doing the oil change yesterday, oil did start coming out of the exhaust. I've heard of oil consumption on these cars but almost a gallon of oil in 400 miles??? That's crazy!

terrasmak

iTrader: (8)

I would try a PCV valve change first, they do suck up oil when it goes bad.

Tom B517

Just an update for everyone: Changed PCV valve and did another oil change after 550 miles. I was able to pull 2 and a half quarts out this time instead of 1.2. I am wondering if anyone has any idea what the issue is before I tear down and rebuild the motor or buy a low mileage used one? Thank you for the help everyone.