Oil Pressure/Temp Gauge

  1. My model of MX-5 is: __ NC
  2. I’m based near: __Liverpool
  3. I’m looking for technical help or recommendations on: __oil press/temp gauge

Here goes…with my first post on MX-5 OC !!!

Since becoming an MX5 owner inside the last month (and absolutely lovin’ it) I’m thinking about installing an oil pressure/temperature gauge because I’m one of those fussy peeps that likes to know about these things.
I read that the installed oil pressure gauge isn’t the real McCoy.
Has anybody (I’m sure you have) installed one of the above

Thanks in advance

Hi, we have installed oil pressure, temp and water temp gauges on our NC. We used a matched set from eBay with pressure sender as opposed to oil tube to the gauge. The oil temp uses a modified sump plug for the temperature sender, and a small manifold for the pressure gauge shared with the pressure switch for the std gauge. We have also installed an oil cooler as we regularly track the car. The gauges sit in a triple binnacle on top of the dashboard, fixed to the grill on the top of the dash, this makes for easier fitting/removal.

If I get time later today, I’ll take a couple of pictures.

The oil pressure reads 80psi on startup and goes down to 20psi on idle when hot. On hard acceleration oil pressure can go as high as 100psi. Oil temp matches water temp after long runs on warm days, i.e. 90c. On track, oil temp stays pretty even, the oil cooler doing it’s job quite well.

These were all fitted as a result of the engine losing tension on the piston rings at 99k miles, which meant it used a much oil as unleaded. The engine was totally rebuilt by Scholar Engines who also advised us on the gauge pickup positions and oil cooler configuration.

Hope this helps.

It’s been said that the oil pressure guage is a false guage, but i’m going to appeal to common sense.

With the absence of an oil warning light, the guage must have some functionality.

The car has an oil pressure switch, but instead of this extinguishing a yellow light, it sends a signal to the ECU, which in turn interprets the oil pressure and therefore sends a signal to the gauge.

If they did this today, I dare say it would have an LCD display showing the (calculated) oil pressure.

So whilst it might not be a true guage as such, it will have some bearing on oil pressure, and undoubtedly more indicative than just a yellow light.

In other words, It’s not just a made up needle that moves at random.

I’m afraid to say you are totally wrong on this one Keat63.

Disconnect the oil pressure sensor and the gauge still does it’s happy little dance, mine is disconnected. The only time that sensor does anything is below 7 PSI where it then connects the attached wire to ground and the gauge stops moving, no other warnings.

I have a pressure gauge attached to the output where the original sensor fits, it’s nice to know what the car is actually doing and being forwarned before anything serious kicks in. If I get 20PSI whilst driving down the motorway I know something is wrong before the engine gets starved. Is it likely to happen? Probably not but I’ve got a gauge to look at now so it feels like a race car!


Here’s the pictures of the gauge installation.

1 Like

well you learn something every day

Thank you all for the swift replies. Mike-P, nice touch with the photo too ( I’m wondering if you can find me a link to that ebay purchase you mention) Well…I have to ask.
Anymore replies. I’m all ears !!

HAGWE everybody,

I’ll try and find the link for you.

Thank you again

Here you go, this is a link to the oil pressure gauge, the others link from there.