A question about oil pressure sensor on the NC2. I just came across some information on the net saying that the pressure sensor on models 1995 and onwards is fake.
Can i have some confirmation what’s going on?
Hi George
some good info here, scroll just over halfway down.
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Thanks 
“Ah now here is where it gets interesting, the OP gauge in an NC is actually fake, it isn’t actually reading oil pressure at all, but mimics it perfectly for a normal healthy engine. What the ECU does is take a signal from the engine water temp sender and also reads engine RPM, it blends these together to make the gauge work exactly as an OP gauge should if the engine is healthy…”
Is what it says in the article and I never knew that.
Thanks for the heads up UKPenfold .
It’s dismaying when you realise that not only is the oil pressure gauge completely fake, the oil pressure sender is not fail safe either. The ECU relies on a lack of signal from the sensor to determine when the oil pressure has dropped below about 7psi. If you disconnect this sensor, nothing changes. If the sensor fails, nothing changes.
I fitted a proper oil pressure gauge for 2 reasons. 1. I’d like to know before my engine goes bang. 2. Gauges are cool.
The engine temp gauge is nearly as bad. It’s not fake but it reads normal from about 55 degrees c up to about 110 degrees. By the time you notice the gauge has moved it’s too late.
I fitted a proper water temp gauge for 2 reasons. 1. I’d like to know before my engine goes bang. 2. Gauges are cool.
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Where did you fit them gauges? I don’t really fancy loosing a vent.
If i get access to the ecu parameters via the ecutec module i wonder whether i can get the actual reading from the sensors
Mx5parts do a 2 or 3 gauge mounting that goes in a single din radio hole. I have a double din adaptor with a single din stereo and the gauges fitted underneath. Its very neat and could almost be stock. I have a picture somewhere I’ll dig it out if you’re interested
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Yes please mate. Thanks
Thanks dude. So basically change the pressure sensor and add the temp and pressure gauge? Ok will probably be asking some questions via pm. Many thanks
Pretty much yeah. I used a t piece with an extension so the original oil pressure switch still works. For the water I used an insert in the heater hose rather then the original sensor position at the rear of the engine just because its much easier to access than the rear of the engine. To figure out which hose to use I started the engine and felt which hose got hot the soonest. Using the heater hose also meant that the original sensor is undisturbed so less likely to leak
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Just another solution fitting the gauges. This is a bit expensive but i think it looks good and is a neat solution. Less hassle and removing an additional expense changing the radio ( I still have the bose radio)
Im gunna check whether that’s actually 3d printed or not. If it is i can probably do a better job designing this but my concern if its a hot day it will deform. But a solution like that is probably better for me.
Looks like a neat solution. Right in line of sight too. Lmk how it goes as I might get one. I’ve been hankering after an android auto setup which are pretty much all double din.
Hi dude, I was looking at 2" gauges these seem a bit steep
where did you get yours (and the sensors)?
George
From memory I think it was demon tweeks. I found it funny that my wife has an account with them
thanks will have a look.
Is it just the NC that’s like this or is it a Mazda thing. Had to renew turbo on my daughters Cx5 recently and no oil pressure light or gauge so knowing when oil pressure was up was tricky.
Not sure how many other cars are affected but its definitely an issue for the nc
Updating this up. I now have an innovate motorsport digital oil pressure and temperature gauge
For reference:
The Mazda oil pressure switch has a 1/4 NPT male thread
The oil pressure sensor provided in the innovate motorsport kit has 1/8 NPT external thread.
The oil temp sensor provided in the innovate motorsport kit has 1/8 NPT external thread
A few questions
My NC is not boosted but I do use it on track a few times a year. I’m now wondering whether there is any actual benefit measuring the oil temperature. What do you guys think?
I’m wondering where would it be the best location to attach the oil temperature sensor? The easiest would be to buy an sump plug with an adapter on it to fit the pressure sensor but I’m not too sure as its not neat solution. Another ideas/suggestions for a good location?
For fitting the pressure sensor I was intending to use an 1/4 NPT thread adapter and a braided hose to move the location of the pressure sensors and secure the attachment on the chassis. I was intending to fit the old and the new pressure sensor. However it would make life easier not to bother with the old Mazda oil pressure switch - however I’m not sure if the ECU would throw an error if there is no resistance/reading from the switch. Does anyone know If I do not connect the OEM pressure switch the ECU will have a fit?