Hi guys i have a problem, i changed the engine with new one from mazda a week ago. Now, when i'm driving, the pressure gauge star to reach low pression and normal pression two times every drive. The oil warning light is off and the engine oil are present.... what hell i doing my car??!?!

 

The gauge fluctuates? if so then you you need to properly test the oil pressure as outlined in the factory service manual. Do not drive it if the gauge reads low while driving. It could be a bad pressure sending unit but it could also be bad build.

 

low and normal a few times.... but the oil light still off!

 

The oil light will only come on if the level in the pan is low. Oil pressure issues are serious. If it shows low while driving then you may have a serious issue. You need to get the issue checked by someone qualified to do so.