Hello, I am planning to swap to the 2.5 because I got rod knock in my 2.3 (still knocks with brand new bearings) and I have questions.

• what year of 2.5 engine do I get/ will fit?
• why can’t you just drop it in and use the Mazda wiring harness (not complaining about it, I’m fine with doing it) just want to know

that’s it for now, but I’m sure I’ll come up with more questions. Just trying to research before I pull the trigger.

thank you for your time!

 

I think all years of the Duratec 2.5 work. As I understand it, you still use the Mazda wiring harness (after the manifolds and sensors are swapped).

 

thank you! I just don’t want to buy the wrong motor and be **** outta luck.

 

Check over on some of the other Mazda3 forums, they have very detailed threads on the process. For some reason the swap is not popular here.