I've noticed my oil pressure is slightly higher lately (at 5000 miles) than when originally bought the car. Trying to decide if it is a good sign (i.e., stronger oil pump) or a bad one (i.e., fouled oil line or filter). Does anybody know where the sensor is located between the oil sump, oil pump, the filter and the engine? Anybody else noticed this increase as well?

 

The oil pressure sensor in the RX8 is just a dummy switch, i.e. it only sends two signals- no pressure, or 'ok' pressure. If you've seen a change in the needle placement, it's either your imagination, or one of the ECU flashes changed where the needle stops for 'ok' (which I think I recall somebody else mentioning as well).

This is one of my biggest pet peeves of the '8- for a $30k high performance sports car, I really expected a real working OPG.

 

Hmmmm....... what a waste of the instrument cluster!
Should have put a voltmeter or even a water temp gauge there instead.

Anyone notice that all these new cars only have warning lamps and no longer any gauges?

I reckon its a conspiracy between Autometer and all the manufacturers so that all the ricers will buy more of their products. LOL

 

i noticed that my oil pressure needle sits slightly higher since M.

 

How do you know it is a dummy unit? I recall when I top off with 1 qt. of 10W40 mid-oil change, the needle shifted higher with 1 unit. After the dealer changed the oil next, dropped back 1 unit. Now, it is 1 unit up again though I did not do anything this time ;o)
The car is new, came with M already. So if the indicator is dummy, it does have at least two very close positions ;o) Still, where is the pick-up sensor located? Just for curiosity.

 

You will find a real unit fluctuate rapidly, changing with engine speed and temperature. The fast movement scared consumers and they would bring the cars in for service. Because of these consumers, manufacturers put in an idiot lights shaped in a dial.

 

Even if it were a working OPG, it's not a oil level gauge... adding oil wouldn't change the pressure. A real working OPG doesn't sit in the same place either- it changes constantly while you drive as the engine warms up, and how high you rev (which is why Mazda stopped putting them in, as people not familar with a real OPG thought the fluctuating needle was a problem.

 

To answer your second question, the oil pressure switch is located on the upper rear right side of the motor, buried below the oil filter mount.

 

From JIM MEDERER of Racing Beat

http://www.rxtuner.com/farticles/BeautyandtheBeat.pdf

"Here’s some of information that we uncovered that we really found amusing! When you look at the instrument panel, it appears that you have an Oil Pressure Gauge. Well, not really! During our research we found that there is no Oil Pressure Sender on the engine—only an Oil Pressure Switch that turns on and off at about 0.5 kg/cm2. When you start the engine and the oil pressure reaches that amount, the switch sends a signal to the PCM - which sends a signal to the Instrument Cluster to display a fixed reading of about 60% of full scale on the “Oil Pressure Gauge”. From then on, unless the pressure falls below 0.5kg/cm2, the Gauge reading doesn’t change - it has no way of knowing the actual oil pressure! This is not a problem since rotaries rarely have oil pressure problems, but it is a little misleading to the driver—he thinks he knows what the oil pressure is, but he doesn’t!"

 

OK, I guess the good news is that I have some pressure. The bad news is, too bad if I care to know how much Thanks anyway - one less thing to worry about - according to Mazda... Keeps us focused on the RPMs and speedometer. Hope those work

 

They do work, although they aren't terribly accurate

 

What would it take to make it a real oil pressure reading unit, a new sensor in the engine? The gauge seems OK as it is a voltmeter of sorts...

 

Man I've seen this before, someone was making headroom on it... mmmm Time for a Search!!

 

It won't be possible to use the existing sender and gauge.

Like most details on this car, the ECU gets in the way. The sender sends its 'on-or-off' signal to the computer, the computer tells the gauge cluster 'oil gauge to OK position'.

RX-7s add a new sender, between the filter and mount, and use your own gauge.
.
.
.
doc

 

thanks guys...that explains the constantly high reading and I did noticed it NEVER moved...oh well...it is funny mazda dummed down this one on us

 

Yeah I notice my oil pressure gauge always reads slightly highter as well.

 

with this so called dumby oil pressure sensor can it be swapped out for one or does the ecu rely on it?

 

I don’t think the ECU will allow the engine to run with out it. Installing an additional sensor isn’t any issue, but leave the factory switch sensor alone.