Combination Oil Sender. Why does no one talk about this?

SonicVQ

There is a third option:
Remove the low oil pressure switch (it turns on the light at < 5 psi!!)
and install the gauge.

As I see it, since you have a pressure gauge, you can detect low oil pressure before the light turns on... for example < 14 psi.

The oil pressure switch is not used by the ECM.

The oil pressure switch is wired directly to the IPDM/ER and when it sees low oil pressure, the contacts close and that ground the signal. Then the UPDM/ER sends a CAN bus message to the cluster to turn on the red low oil pressure light.

If the switch is unplugged, it never get grounded and the low oil pressure light will never turn on.
BUT you have the gauge, so nothing to worry about!

I did this on my G37 just over a year ago when I installed my oil pressure gauge.

40 to 332

Recognize that if you elect to go with the ProSport Oil Pressure Sensor, you'll need to install a 1/8 male BSPT to 1/8 female NPT adapter since the OEM port is BSP (i.e., metric).

SonicVQ

Excellent add!

Note:
This older style and larger oil pressure sensor uses a flexible tube/bellows to push/pull a wiper/contact across a wire wound resistor. This results in a resistance of 3-160 ohms and only works with older analog gauges. From my experience, they are not accurate and don't work well for long, as they wear out quickly due to the constant moving of the "wiper"


Today, most pressure sensors are all electronic, temperature compensated and provide a voltage of 0.5 volts for 0 psi, to 4.5 volts for 150 psi. (or 4.5v @ 100 psi)

As you can imagine, the electronic pressure sensor are more accurate, quicker to respond and durable.

phunk

I have expressed the same opinion for many years... the stock idiot light has no real purpose once there is a gauge in the car, especially a gauge with warning light and/or sound. Lots of people seem to be opposed to the idea of ditching that light. Of course a small part of me would slightly prefer it still work, but I have a much stronger preference to less clutter and crap in the engine bay if I can avoid it.

But here is the best reason to just put the pressure sensor on an oil sandwich plate: The cast upper pan is *extremely* thin and weak at the oil pressure port. Many many people have cracked the pan messing with the sensor or installing a different one. Let along hanging a large bulky one in that port like shown in the original post here, I feel like a good pothole will make that thing break the bung off the pan . So at this point, having cracked my own upper oil pan pressure bung, and knowing so many others that have, I am hesitant to screw with the stock sensor port at all now. Replacing that upper pan is a serious job that you do not want to have to do if the engine is in the car.

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SonicVQ

Understood... I read about others having that same issue and not just on this engine.
Pegasus Auto Racing has an excellent article on NPT fitting and how much to tighten the tapered NPT fittings: https://www.pegasusautoracing.com/do...ocID=TECH00097

In a nutshell, they recommend any 1/8" NPT fitting only needs 1.5 - 3 turn from finger tight.
When I put in my pressure sensor, I used a thread sealer and did 1.5 turns and started the engine to check for leaks. I had a small drip, so I tightened an addition 1/2 turn, and all is good to this day.

In the spring I am going to put on a sandwich plate with a pressure sensor.
This will place the pressure sensor BEFORE the oil filter, and the factory located pressure sensor will measure the pressure AFTER the oil filter.

Then I will be able to test the pressure drop for different oil filters, by engine RPM and oil temperature.
I am really curious to see how much pressure drop difference there is between oil filters.