Well, as the title states I'm having trouble with the whole swap. My original engine blew after sucking up too much water, so I purchased a k20a3 to swap to sub the k20a2. Long story short I swapped in the a3 and now it wont turn on but there is a small clicking/tickingcoming from the engine. Can't tell if its the head or block or even if the swap was supposed to be interchangeable between the 2 diff cars. Any info on this subject would be greatly appreciated. thanks

 

why would you downgrade?

Any ways did you get the key matched to the ecu? make sure you are running the right ecu also...