I have a 1983 N/A 280zx 2+2 that started making a weird clicking noise from the engine. What could this be? It seems to be coming from the back of the engine and almost sounds like it's coming from inside the block.

 

Sounds like an exhaust leak from the classic burnt manifold gasket at cylinder 6... due to a loose / broken manifold stud.

 

That sounds pretty technical. It is expensive to fix? Could I do it myself, or am I better off throwing it to my mechanic? Thanks

 

It means you get to remove the intake and exhaust manifolds. If the stud broke off in the head (common), you get to drill it out and extract, or if it broke flush with the head you can weld on a bolt and back it out. It's a 5-10hr job the first time with the egr pipe and exhaust coupler being the most suborn parts to remove. The only special tools you need is a swivel and extensions for your 12mm socket, and a mirror to see the hidden nuts under the intake.

And... there's a write-up for that: https://www.zdriver.com/forums/240z-...-gasket-18779/