Odd Oil Pressure Symptom
 

I was at a track event today and when I started the Z to go out for my second session my Glowshift oil pressure gauge was not reading any pressure at all. I figured the gauge or sending unit had died when I realize the oil light was on at the dash too. I blipped the throttle and the pressure instantly began reading normal levels and the dash light went away. I went out for my session and everything seemed fine. After lunch, it happened again so I cut the day short. It’s doing it when the car has a chance to sit for a bit. If you blip the throttle it always reads normally and if you then turn it off and back on it’s fine. Gallery gasket job was performed last year and it has the upgraded Boundary oil pump gear. Any ideas?

You’re a brave man to go out for a session right after having oil pressure issues…


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Change the oil and cut open the oil filter. Something has gone wrong. If you see metal flakes and crap in the oil filter, new engine time.

I plan to take it to SOHO tomorrow. I’m going to explore some options between throwing a low mileage used motor in it to a mild build.

Put a oil pressure gauge on it and see what the pressure is.

It has an aftermarket one installed. It was not registering any pressure until the throttle was blipped. I cranked up again this morning and it seems fine. I dropped the oil and didn't see anything weird in it. I’m thinking maybe a blockage in the oil passages. I probably went overkill on the RVT when I changed the gallery gaskets.

Possibly oil pressure relief valve in pump stuck open. Happens on GM trucks sometimes, lifters will make noise etc start to rev engine a few times and all a sudden pressure is back and lifters fill etc. Sounds horrible and then new pump fixes it.

Well gallery gaskets should not need ANY RTV. I did coat my OEM new gaskets in really light RTV at the same time.

Your best bet is to install a manual gauge or wire up the glowshift manually so it can give you as quick of a reading as possible.
Depending on your findings I would change the oil and filter and inspect the filter as previously stated.

Continue to monitor this.

Thanks for the response. I should clarify. I didn't put any rtv on the gallery gaskets themselves but I did use a lot reinstalling the timing cover and oil pan. It’s plausible that some excess detached and could have lodged itself somewhere. I’ve changed the oil this point, inspected the old oil and filter. I even ran a magnet and a light through the old oil and didn't pick up anything. I used a Harbor Freight external gauge in addition to the one thats already installed and they are both reading normal pressure. I have no idea what was causing it but I will definitely continue to monitor it.

With the analog gauge what is the minimum pressure you see at cold start and for how long until you have to blip the throttle?

Cold start I’m at mid 90’s PSI. I haven't been able to replicate the problem since the track event. I’m just going to keep running it as is. If something fails I’m OK putting a new engine in it.

Did you get oil pump gears only or did you get complete pump assembly from boundary?

Just the gears. The OEM pump is still being used.

That's low, it should be in the 100's. I beat you have an issue with the boundary gears. It has happened before on a new engine build. I suggest you go back to a new Nissan pump or get the Nismo pump. You could also be seeing
bearing related issues. Either way, you have an issue going on.

I installed their pump with their billet cover with 2 relief shims already preinstalled from boundary. Hope it won't give me any issues with oil pressure

These gears with 2 added shims to the relief should be yielding higher cold start numbers. A contaminated relief should yield higher numbers.

Lower numbers can be contributed to excess bearing play, damaged gears, leaking oil pump housing, blocked oil pick up, relief collapsing due to really high initial pressures (somewhat unlikely)

Throw oil filters every 1k miles and open your old ones, these should give you better insight if you're wearing prematurely.

I didnt use any shims. Also, it’s been warm the past few weeks. The PSI mentioned is on a 85-90 degree day.

For what it's worth, the only time I have ever broken over 100 PSI on this particular car is a cold start in the Winter.

I called Boundary yesterday and they do recommend shimming +2 for the VQ platform. If I would have been more patient and done more research I would have figured that out before buttoning the engine up last year. Lessons learned. I purchased a low mileage replacement engine yesterday as well as the full pump assembly from Boundary. This will give me a fresh(er) motor to track with and I’ll keep the current engine on a stand to tinker on.

I keep reading that these pumps should be shimmed.

The extra pressure will do numbers on that relief.

Luckily for you, you can access the relief just by taking off the oil pan, may want to try this before just in case.

As previously mentioned, I'd guess the oil pump pressure relief valve is sticky and stuck open. Shims won't do anything to fix this other than just making it harder to open that valve in the first place. Replace the relief valve, it should be accessible if I recall right with only the oil pan removed.

Yes and no, the added volume and pressure this pump puts out might be triggering the relief too early causing a massive dump of pressure making it seem like it's sticking which is why a shim would work. It would compensate this force by compressing the spring a bit more.

I ended up getting a 2015 motor with 39k miles on it from an Infinity. I am having a shop install a full boundary pump assembly with +2 shims as well as remove the old motor and install the new one (hand surgery has me out of the garage for a while). Once it's all said and done I will do a new pump on the old engine and keep it as a spare. Question, the Infinity has the stock oil cooler so is that just extra cooling power coupled with my 34 row?

My oil pressure findings on my newly built engine with complete boundary oil pump with billet plate and 2 shims:
at 190-200F oil temp it runs about 35psi idle. Higher rpms and more load I already see 130psi or more. Definitely there is more oil pressure than stock pump. I have my oil pressure sensor connected to oil filter relocation sandwich plate.