I just boght 3.0l srx engine. Turns out engine has 194k miles. I was planing to change timing chain since engine is out of the car. After i took out valve cover it seems timing chain is pretty tight. Is there a way to tell if timing chain needs replacement or i should just do it? Also as you can see on photos one side of the engine is really dirty from old oil. Any way i could clean the engine? Please see photos.