I wanted to check to see if the characteristics I've been seeing are normal on my car. I searched for low oil pressure issues but haven't found one that discusses my situation. I've already checked the FSM and there's no indication of whether my car is having issues or not. Here goes:

At any rpm lower than 3000 rpm the oil pressure guage show that I have 0 lbs/sq. inch. At about 3500 rpm is goes up to about 15 lbs/sq. inch. Above 4500-5000 rpm the pressure is at what I understand is normal pressure, 60 lbs./sq. inch. It's weird to see oil pressure fluctuate depending on rpm.

I've had the car for about 3 weeks. I changed the engine oil 100 miles ago with Castrol GTX 20w50 and used a Mazda OEM filter. I don't think the oil pressure fluctuated like this before the oil change. I currently have oil levels exactly at the middle of the dipstick. I'm planning on adding more oil to bring it to the top of the stick as per the FSM, from bottom to the top of the dipstick, acceptable levels is 1.8 quarts (quite a bit).

The only other thing I've changed is the transmission fluid lastnight. Is this normal?

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/oil-pressure-too-low-idle-614723/

 

Thank you sir. I'll look into it and thank you again for keeping me sane.

 

This is off-subject, but after reading the link Mahjik posted I have to ask. I've been told numerous times not to put synthetic oil in my FD. Is that correct? If so, why? I had assumed it was becasue it would not burn, but if this other thread is correct I'd have to question the reason. Wait..I just did.

And thanks to Mahjik. Don't know where he came by his knowledge of rotaries, but he has yet to lead me wrong.

 

There has been debates about the ash content of synthetic oils. I believe the issue was more with the older synthetics which were around the time the car was created. I don't believe the issue is as prevalent today. Luckily, the rotary is not the only car to purposely burn oil so synthetics were forced to evolve to complete.

I do believe its a bad idea to switch to synthetic on an engine (rotary or not) with quite a bit of mileage on it. Synthetic is much better at carrying away deposits. This is the reason you hear people talk about synthetic oils creating oil leaks. If there is a leak which is suppressed because of grime build up, switching to something with can better at getting rid of the grime may expose the leak by removing what is keeping it from leaking. This typically happens with higher mileage motors which is why it's not recommended to switch.

I personally had this happen many years ago with my wife's old car. It had about 90k miles on it and I had a quickie oil change place put synthetic into it. Within a few days it was sprouting leaks all over the place.

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/oil-pressure-1992-jdm-fd-679220/

Oil pressure sensor only lasts between 60 and 80,000 miles,
$83.00 from mallory Mazda, $125 from other dealers.

 

I took the FD to the place I usually take my other cars for oil changes. I have usually changed the FD's oil myself but dont feel like dealing with it and the mess now. They wouldn't change the oil because the gauge says the pressure is low. Didn't matter what I told the asshat, he wouldn't budge. "that's our policy, blah, blah, blah." What a bunch of BS.

Drove down the street and had it changed somewhere else with no problem.