I have a 08 Mazda 6 with the 2.3l engine and I'm trying to find a short block for it, what is the difference between the Mazda 6 engine and the Mazda 3 engine?

 

Don't bother, the 2.3 engine has a horrible reputation for longevity; instead, buy a complete 2.5 liter Ford Duratec (basically the identical engine as the Mazda 2.3, but with some very important internal upgrades), swap over the manifolds, and put that in. Not only will you have a more reliable engine, but it will be more powerful and yet return the same fuel economy.

 

Will the 2.5l bolt up the same and run with no program change or will I need to replace the pcm also?

 

Assuming you move the manifolds and sensors from the 2.3, then it should bolt up with no need for a new pcm. Search the internet, there are plenty of Ho-To resources on the swap.

 

I found alot of how-to videos and it seems pretty simple but all of them show an automatic, will the 2.5 bolt up to a manual trans?

 

While I've never done it, my understanding is there is no difference in the bolt up for automatic versus manual (other than the obvious differences of bolting up a torque converter versus a clutch assembly). Said another way, bot manuals have the same bolt pattern at the transmission to engine interface, and the crank has the same bolt pattern regardless of whether you're bolting up a flywheel or a torque converter.

 

I finished the swap and the 2.5 bolted up to the manual trans with no problem, I had some issues getting the crank pully and sensor timed but got it figured out, now I have a random misfire code, any common problems?