Idle oil pressure at 0 psi?
 

Hey ya'll I recently installed a GlowShift oil pressure gauge into the stock dummy oil pressure switch location (under the oil filter). I've noticed that when the car is fully warmed up, the PSI dips to about 4psi and after a long drive comes close to 0. The gauge functions completely normally outside of idle however. I'm getting the usual ~10psi for every 1000rpm.

I did have to use a brass adapter and its on there pretty tight. I used teflon tape on the adapter itself but the sensor plug had thread locker on it.

Anyone know why its reading at 0psi? Car is mechanically sound as far as I know. Idles beautifully, etc. I'm thinking it might just not be a very accurate gauge?

That would be my guess.


humfrz

Test against a different gauge. What pressure do you see on first cold start in the morning?

Don't have another gauge to test unfortunately. However, I'm almost certain its not actually that low since the dummy light when it was still connected has never turned on, and IIRC the dummy light turns on around 2.5psi or so.

Cold start in current Toronto weather was around 105psi (Don't really remember from earlier today, but it was a bit over 100 which is to be expected).

Yeah, I'm with you. Probably nothing. Even a bicycle pump would do the trick to confirm; some hose and a couple clamps...

Toyota specs are 7 psi idle at 172 degrees oil temp.Of course the hotter the lower oil pressure will be. I used to show as low as 4 psi at idle at 220 degrees. I just raised my idle from 750 to 950 rpm and now my oil pressure never drops below 20.

http://www.ft86club.com/forums/attac...1&d=1360605963
I found this chart. Last time I ran torque on my phone on a daily drive I exceeded 200F. Since its speced at ~7psi at 170F like you said it does sound normal for the pressure to be even lower. This seems kind of low for a car though doesn't it?

Also in this video I don't see his oil pressure dip below 10psi on a normal drive! But then again it might just be a colder area in the video

[ame="https://www.youtube.com/watch?v=cDfFJ5s6IDg"]FRS - BRZ Oil Pressure and Temperature Tech FA20 - YouTube[/ame]

I avoid gauges made by Glowshift for this very reason. It may be accurate enough while you're driving around, but down low and up top they are useless, which is often where you need them to be accurate the most.

I also avoid Prosport for this reason, and the rate at which I've seen sensors fail. They have some nice features and price points, but I can't get down with their quality issues.

I like: Defi, STRi, AEM, Innovate, Stack...

I'm using an Autometer mech gauge.

Autometer stuff is generally good too.

I work on Japanese cars, and the occasional BMW or truck, so not many people ask about the Autometer stuff. :iono:

I like gauges, something our car falls short on. So I made my own cluster, complete with cell phone holder.

Under it I also have the "Scan Gauge" with read off the ECU. All my other gauges are direct on their own sensors.

The nice thing about the scan gauge it is also a code reader and can be used to clear codes.

Just went out for a short drive to test it. At 176F idle it sits around 10psi which is basically to spec. I think my conclusion is the gauge only reads "0" after hot idle because its not the most accurate. I guess in the end its still better than a dummy light ¯\_(ツ)_/¯. Maybe I'll get a T Fitting installed so I can run both.

Interesting setup.

I like the inclusion of the scan gauge.

Is that a mechanical Bosch oil pressure gauge? I generally dislike those as you usually have to run a hot oil line into the cabin, and those lines can kink/wear through etc. Additionally, these cars with 0-20 run over 100psi cold, and even higher with heavier weights.

Is there an autometer electronic? I like the stepper motor ones too because they smooth the output enough to not be distracting, while still being quick enough to tell you what's happening.

That's A solution but not THE solution, which is to get a higher quality gauge that can give you accurate results.

Yes, but I use copper line instead of the plastic that comes with the gauge.

Solid improvement. Still hot oil in the cabin. It bugs the slightly illogical side of me.

The same one that dislikes oiled panel filters because it puts oil in front of the MAF. Not ideal but not the worst thing in the world, and if done correctly really shouldn't cause a problem.

:iono:

What oil brand weight are you running?

For what it's worth, I kinda put this to the test. Replaced the dry-flow filter (I think it's a Works, I was expecting it to be stock/OEM replacement) in my new to me BRZ, with my used Perrin panel filter which I cleaned and oiled with UNi foam filter cleaner and oil.

Drove it for a week, then pulled the MAF. It looked spotless. Still cleaned it with CRI MAF cleaner anyway. I like tinkering with my car on the weekends so I don't mind cleaning and re-oiling the filter and cleaning the MAF every now and then.

The filter oil does get around the inside of the airbox though. It looks to be catching a lot of dirt before the intake tube.

For me it's 50% "Oil belongs in location A not location B", and 50% removing the change for human error, (over/under oiling.)

Imagine accidentally spilling a bunch and not being able to get enough of it out.

I run the AVO dry flow, it's dry, I'm happy. :)

Motul 8100 0w20

I hear ya. I tried a electronic sending unit digital gauge and didn't like the fluctuations I was getting. Also being almost 70 I guess I'm kinda of old school.

Hahaha understood.

I grew up with a 'cutting edge hot rodder' for a dad.

EFI on Chevy big blocks on water shoved into the back half of a beetle, destroked 427 in an anglia, blown 454 in a rusty, mismatched paint malibu wagon, etc.

He was pushing the boundaries and making the old school guys uncomfortable when he was getting into it, and when I started showing him low displacement boosted engines, stepper motor powered gauges, EBCS's, and low(er) profile tires he was uncomfortable too.

He's come around to it, but it's as fun to teach him the new ways and help him make improvements as it is to apply one of his old school theories to new cars when I can't seem to resolve something.

(DIY Cryotreated axles, anyone?) :thumbsup:

We just recently started a collaboration of sorts. I've always helped him with his projects, and he's always helped me with mine.

But now, we're grafting E36 M3 suspension and driveline into a 68 1/2 notchback mustang with a 289k code, fully gutted, tubed where appropriate, full racecar type build.

Sounds interesting.

I'm going crazy with trying to ensure accurate readings from my gauges. Yes, I purchased Prosport gauges. My 176 degree idle does seem to be around 8 PSI and I'm running 10w30 oil. However, PSI mirrors my RPM (30 PSI @ 3,000, 50 PSI @ 5,000, etc). I've got the sensor in the oil gallery plug on the top of the engine. I'm trying to get Oil temp and pressure, but a tee fitting affects temps.

I threw a rod bearing and had the engine rebuilt and it seems to be burning oil almost a quart at the last track day and occasionally blows big cloud of smoke at startup. So I don't know if my lack of pressure could be indication of a mechanical issue as well.

Sounds like you need to do a compression and leakdown test.

That appears to be normal idle oil and running pressure according to the FRS/BRZ Repair manual. A table of the expected oil pressure levels was posted by the OP on the first page: https://www.ft86club.com/forums/show...86&postcount=7

My car (which I presume has no issues) idles at just above 0.5bar (which is about 8 psi) per my gauge with sensor located on sandwich plate just upstream of filter. Redline seems to run about 6.5bar (95psi), so about on a "mirror trend" as you call it between RPM and pressure. This is on spec with the OEM oil pressure table above.

Like mentioned, you should look somewhere other than pressure in this case for signs of the leak. A tiny hole may not show up as a pressure loss at extended distance, but it certainly can push fluid

Also, don't hoon the car when the oil is cold. When you first start the car, oil pressure is 8bar (120 psi) at 2k RPM, easily goes over 10 bar (140 psi) by 4k PRM. Already 30% to 60% higher than redline warm...