First off, I have read the fact sheet at Mazdatrix about oil pressure, and I do not think the "O" ring is the problem. It is an '87 RX-7 TII. The oil pressure guage reads 30 psi at idle after the engine warms up, but while driving down the road at 60mph it reads any where from 45 to almost 60 psi. I bought the factory

service manual so I know all the possible reasons for the pressure would be reading low. The first thing I want to check is the oil pressure guage unit (locate just below the oil filter) but I cannot find the oil pressure gauge tester (looks kinda like a expensive tire pressure guage) anywhere and the local dealer does not sell tools. The Mazda part no. for the tester is 49 0187 280. Does anyone know where I can find it. Thanks.

 

He's right, if you find the tool at a dealership, its probably gonna cost a fortune. Also, if you have a little extra cash, purchasing an aftermarket Oil pressure gauge from Autometer or another respectible company will be a good way to tell if its the gauge thats busted. And Autometer's guages are only around 40 to 50 bucks. Not to mention, mazda was never known for their great gauges for the rx7, the factory units have been known to be WAY off...or just not useful at all!