Hey, I just bought my first rex last Tuesday. It's an '89 n/a. So I started doing some maintenance and tune up type stuff last week, starting off with an oil change. I looked around the board and saw that many people use 20W-50. I've always used Castrol GTX in my truck and like it, so I picked up some Castrol GTX 20W-50 for the rex. After the oil change, the engine seems to be louder, making a whining noise kinda like a turbo or something. I don't remember hearing it before, would the belt driven fan make this kind of noise at 5000 rpm? Is this noise normal for rotaries? Perhaps I should use a heavier/thinner oil?? The engine seems to run the same otherwise.
Thanks for any help

 

one other thing....the oil pressure as reported by the gauge is the same as it used to be....just a smidgin under 60 psi

 

10W30 I believe in mine. Can't remember what mazda recommends offhand, check your owners manual.

Only wining noises I hear are flywheel when I shift at 4500 rpms

 

Ummm. The winning might be some sort of vac hose disconected.. Thats what I notice anyways.