What should a miata in decent running condition read on its oil pressure gauge? I thought i noticed mine running a bit low at around 15. I checked the manuals but it didn't say anything about it. Any help would be great since i finally have it back on the road.

 

factory guage sucks check with a mechanical to be certian i found that once hot my guage was off by 10-15 lbs of pressure to the low side. factory is 20-30 at idle and you should shoot for 10psi for every 1K rpm is what i have always heard to be good.

 

well i think it was around 93-95 so the temperature may have had an effect, how would i check the oil pressure with a mechanical gauge? never had to do it

 

take out the stock sender and screw in the fitting and line for a mechanical gauge then run the motor and observe the pressure. A mechanical guage measures pressure directly with a oil filled tube that actuates a diaphram, and turns the needle on the gauge to its desired location.

 

ah ok, thx for the help... if the pressure is low what would cause it? low on oil bad oil pump?

 

Typical readings cold:
Idle: 30
3000: 90

warm:
Idle: 15-20
3000: 50-60

Cold and warm refer to the temperature of the oil, not the ambient temp.

If you do decide to check with a mechanical gauge, remember that the threaded fitting in the block is 1/8" BSP, not 1/8" NPT. Correct adaptor: http://www.pegasusautoracing.com/pro...asp?RecId=3142

 

oil breacking down bad seals or bearings somewhere

 

i know i need a new valve cover gasket, but i'll check like you said, thx for the help

 

nah Valve cover gasket wont effect oil pressure more like cam, crank bearings and seals, or OP seals as well.