What Classifies As Low Oil Pressure? 2010 370z
 

2010 370z. 83,500 miles / 134,500 kms automatic.

Purchased from a second hand car dealer, in very good condition.

I have had the car for 7 days, and installed a 150 PSI oil pressure gauge today. During this 7 days I've not had the stock oil pressure warning light come on at all.

I've tested the oil pressure with the car on the ground at idle and at 2,000rpm with results as follows:

Oil temperature 80*c (based on stock gauge on dashboard) + Idle RPM in "Park" = 7-8 PSI oil pressure
Oil temperature 80*c (based on stock gauge on dashboard) + 2,000 RPM in "Park" = 36 PSI oil pressure


I don't know what oil is in there currently, but it is new, as the dealer had it serviced prior to me purchasing it and visibly checking the oil it is clear/new looking.

Questions:
How much does a different weight of oil affect oil pressure PSI results?

Are these results of concern?

The 370Z does not have a oem oil pressure gauge. The gauge on the left of the 3 cluster gauges on the dash is an oil temperature gauge. You said that you installed a oil pressure gauge. What does that read? Also where did you install the pressure sending unit?

I think you misread.

You are correct, the 2010 370z does NOT have an oil pressure gauge. But it does have an oil temperature gauge and an oil pressure fault sensor.

I installed an aftermarket oil pressure gauge/sensor, and left the stock oil temperature gauge as is.

I unthreaded the stock oil pressure fault sensor, and used an adaptor like below to fit the stock oil pressure fault sensor and aftermarket oil pressure gauge sensor together.

https://i.imgur.com/leFSy36.png

Missed part of that. Sorry.

I have my sensor in the same location. You're low on oil pressure. You might have a oil galley failure. The only sign that it failed is low oil pressure. or when the engine starts to eat it's self. The warning light doesn't come until 5 to 10 psi. After it's too later.

Here's a thread I started about oil pressure.

http://www.the370z.com/engine-drivet...ure-gauge.html

7-8 psi at idle is pretty dang low. I would expect that your gallery gaskets are compromised. You'll probably see pieces of the gasket blown out or find some bits of gasket in the bottom of the oil pan. Recommend replacing them with the EPS kit that includes new hardware.

This is going to seem like an odd question, but is your 370 "sunset orange" (that was blue?)

:confused:

No, it's a fresh import from Japan in white.

Got it.
I saw an orange 370 at the Golden Cross Hillclimb on Monday and was wondering if it was you.
The roads in NZ are the most fun I have ever driven on!

I honestly would recommend a new engine to be swapped at that point. There's no doubt that you started wearing the bearings with such low oil pressure. No point in doing gallery gasket now.

How likely is this to be a problem?

How much more work is it to check for that, while doing the gallery gasket work?

I had Nissan do a pre-purchase inspection on the vehicle before I purchased it from another dealer. The Nissan tech said the engine felt/looked very healthy, and the compression checks were great.

I've been doing some more thinking about this, while I await quotes from shops to investigate and/or repair.

If I genuinely had low oil pressure, why has the low oil pressure warning light never appeared on the dashboard? And why does the computer not have any fault codes?

Is it possible that if the STOCK oil pressure fault sensor fails, the computer then won't show an oil pressure warning light? Or if it detects NO signal at all from the stock warning sensor, does it automatically show a warning light?

The oil pressure warning light is pretty much useless. It's literally just a fault code if the signal goes low enough (so yes the dash light should come on if the sensor fails). From what I can tell it comes on at about 5 psi - if it comes on you'll be lucky if you haven't damaged the engine.

You would have to take out a couple bearings and see if they're still good, but at that point you might aswell change all the bearings and in the end swapping in a newer block is cheaper $ wise.

Edit: The reason I'm saying this is I had a friend's car that we did the gallery gasket on. Oil pressure was a little higher than yours but still under 13~ psi at hot idle. His engine is still running but the oil is glittery with every oil change.

First step for me would be to drain the oil as slow as you can through a coffee filter with a nice strong magnet in it, this will take a while but the information you gain from it is worth it.

Good news and bad news.

Good news is with the oil pan removed (what a PAIN IN THE *** to remove!) I observed a small piece of gallery gasket material in the oil pan, at least confirming my suspicions.

Bad news is that means the gallery gaskets have gone, and I'm in for a very expensive repair job.

https://i.imgur.com/4IUUH4x.png

EDIT: Also after filtering the oil through a paper mesh coffee filter with a neodymium magnet, there was basically no metal contaminants. There was one very small piece of a silver coloured metal, but it was very, very small and the only thing present.

What is the preferred brand/supplier for replacement gasket sets?

What other items should I replace at the same time? Are some replacements "optional" ie: only replacing the timing chain if it is stretched, or am I better off replacing EVERYTHING?

EPS gasket set.

EPS Tuning Oil Gallery Gasket/Hardware Kit

With the number of miles you have on it. Water pump, thermostat, timing chains and guides.

Up grade the oil pump gears too.

https://www.z1motorsports.com/lubric...6c80dab2898b1b

Is the Z1 Motorsports option any good? https://www.z1motorsports.com/front-...t-p-17916.html

Z1 Motorsports appear to have more of the parts I need, meaning I can order everything from one place, rather than some from ESP and other parts from someone else?

I just experienced the exact same situation a few weeks ago. Installed a pressure gauge, noticed low pressure. I got a few quotes from local shops that wanted $1800-$2500 depending on the shop just for the labor. I ended up doing the job myself. If you don't feel confident about tackling it on your own than definitely pay a professional for it, it's not a small job. I used the Z1 gasket kit that you mentioned.

I've had a quote back from my local Nissan dealership and they sent through a huge parts list. Surely it doesn't require all of these?

Can someone help me figure out which of the below I need vs. don't need? I'm only wanting to replace the gallery gaskets, plus the water pump and thermostat, and then only the chain and tensioners if they are stretched/worn.

(keep in mind pricing is in my currency, not USD)

https://i.imgur.com/RRDtXmF.png

Someone's trying to line their pockets with that list and pricing. You likely won't need most of that stuff and $240 for a water pump is insane - don't let them bend you over like that.

Here's what I purchased from CZP for my gallery gasket job (ignore the PS cooler and ATI crank pulley). Got the gasket kit direct from EPS Tuning (see Rusty's link) and my mechanic sourced a new OEM thermostat for me.

Even doing the currency conversion, that's $160usd for a water pump. A new OEM water pump should be around $75usd or $110nz.

As far as what is necessary...a $60 set of gallery gaskets and some RVT. But, to everyone's point it would be a bad idea to have everything torn apart to replace those gaskets and not also replace the wear items while they are exposed. So what is necessary will be different based on the user. I would without a doubt replace the water pump and thermostat. If the chains, guides and tensioners look flawless I wouldn't judge someone for leaving them be if this was a weekend "I'm going to Starbucks" kind of car for you. If you plan to keep the car, drive it regularly or hard then yes. You should also replace the chains, tensioners, guides and oil pump gears. Those parts would run you about $1500nz. What was the labor quote, I don't see it included?

Ooops... duh :facepalm:

At 100K and planning to keep the car and drive it hard I probably should have done the chains, tensioners and guides. Everything was in good shape though so I didn't bother. I did put in some billet oil pump gears tho.

Labour quote is 6-10 hours at $166 NZD ($112 USD) per hour. This is for a Nissan dealership.

I think what I'll do is order the parts from Z1 Motorsports instead, so far I have this - is this everything?

https://i.imgur.com/7u1eQ3K.png

Except for the oil pump gears, that is exactly what I ordered.

How necessary is it to change the oil pump gears? From what I've read this means also changing the oil pump to new one, as new aftermarket gears shouldn't go in a used pump?

I only use my car as a daily driver with the odd weekend drive (no track days or crazy driving), so just don't know if it is worth spending so much on the oil pump/gears?

Final Update:

After presenting the quotes to the dealer I bought the car from for the repair work, they refused to accept there was a problem with the car, and when doing their own oil pressure test using a method different to the factory manual, they claimed the oil pressure was fine. They also didn't accept the gasket in the oil pan was a problem.

Fortunately they agreed to fully refund me, so I've now handed the car back.

Sadly for me, this is probably the end of the 370z train. I don't want to take a risk on another 370z that will have this gasket failure issue, and there are no 2014+ ones for sale near me.

You dodged a bullet. Now the dealer is going to sell it to someone else without fixing it I bet.