How do you check......?
 

How do you check if the valves are messed up without taking the heads off?

Also, how would you check to see if a coil is bad not knowing which ones work and which dont?

Gracias!

You can do a compression and leakdown test for the valves, not sure about the coils though.

a scanner that can monitor misfire i would think you could determine which coils are bad. and if you suspect a particular one, swap it around with another one...see if the misfire follows