My 04 TL 6MT is knocking/ticking really loudly and on deceleration, there's a weird grinding noise.


Backstory:

Driving and heard a slight 'ticking' coming from the engine. Within 2 minutes, it was much louder, CEL came on (flashing) and the car started stalling when idle. CEL revealed Misfire on Cyl 1, 2, 3, 4, 5 and 6 and the Random Misfire code. Compression test revealed 225 on the rear 3 cylinders, 110 on 4, 10 on 5 and 30 on 6. Leakdown test confirmed blown rings on 4-6. Removed front head, machine shop said it was slightly warped, they fixed that and reseated all the valves and adjusted them. I pulled the pistons from Cyl's 4, 5 and 6, removed the rings which were worn down. Pistons and rods were still in spec, so I put new rings on them and popped them back into the block. I put it all back to together and I'm getting all the same knocking/ticking and that horrible deceleration noise as I was before, but no CEL. Please help!

 

So, turns out the knocking/ticking noise was valve noise. I did a valve job and that noise has gone away. I still have the noise at deceleration. Any ideas?