I have a 96 i picked up and it has some blow by on the motor and i can hear a knocking noise. The knock noise is still there after adjusting the valves. I disconnected the three back injectors because that's where the knock was loudest but it didn't really seem to go away but when i disconnected cylinder 5 it did get a little less. I listened to the motor all over and the place i could hear the knock the loudest was at the transmission which makes me wonder if maybe the flex plate has cracked. Any way to test the flex plat with out pulling the trans> i looked up in there but i couldnt see to much.

 

At idle, foot on the brake, knocking in neutral, what does it do when you put it in either reverse or forward?

 

It does it in all gears.

 

here is the difference between the injector 5 being disconnected and connected. its not a whole lot but i can hear it.

 

Sure is noticeable. Try swapping injectors with another cylinder (#1) and see if the problem moves. If it does, bad injector. If not, it's internal like a wrist pin or rod bearing or....etc.