I think my fabia might need a new engine, its the 07 BLT engine code, do I need to replace it with another BLT engine?? Or will the older ASZ engine work too?

Thanks

If you get an ASZ with all its ancillaries you'll be fine.

I know things like EGR vales and turbo manifolds ay be slightly different but both attached to the same drive parts

I know Chrisw_vrs replaced his BLT with it's blown pistons/cracked block wth an ASZ one

The engine blocks are exactly the same.

So yes u can use a ASZ to replace a BLT..