Idle oil pressure at 0 psi?

[Cubix]

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?

[humfrz]

Originally Posted by Cubix

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

[Ultramaroon]

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

[Cubix]

Originally Posted by Ultramaroon

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).

[Ultramaroon]

Originally Posted by Cubix

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...

[Lunatic]

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.

[Cubix]

Originally Posted by Lunatic

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.

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]

[JazzleSAURUS]

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...

[Lunatic]

Originally Posted by JazzleSAURUS

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.

[JazzleSAURUS]

Originally Posted by Lunatic

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.

[Lunatic]

Originally Posted by JazzleSAURUS

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.

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.

[Cubix]

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.

[JazzleSAURUS]

Originally Posted by Lunatic

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.

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.

[JazzleSAURUS]

Originally Posted by Cubix

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.

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