My rx8 recently cant start at all. I last used it
4 days ago and nothing seemed to be wrong.
Battery still at 11.9 volt. But the engine was
totally silenced when i tried to start it up.
Not enough battery voltage. Recharge the battery and have it tested, if it fails the test replace it then check the charging system just to make sure the output is correct.
Battery has chaned but still a failure. 3 weeks ago i ve added approx 400ml of engine oil. The car was smooth. Will this be related to my problem? No engine sound at all when i tried to start it up
Read the entire answer completely. Recharge battery, it should be around 13.2 to 13.8 volts, then you need to test for battery power at the starters larger wire, if that checks then you need to test for battery voltage on the small wire when the key is turned to the crank position with the clutch pushed all the way to the floor if a standard trans or in park if an automatic, if all those check then you have a bad starter, if you don't have power on the small wire then you could have, a bad clutch switch if a standard or a neutral safety switch if an automatic, faulty wiring, or even a bad ignition switch. Now you could try jumping the large terminal to the small wire terminal on the starter just to see of the starter will spin up, but there will be sparks and the vehicle must be secured so it won't move, so Park if and automatic, neutral if a standard and the park brake set. Now if the starter does spin doing that then you know you have a problem with one of those switches or wiring. HTH