Rough Idle and Smoke after head studs

[J_D]

This is my first post. I have read through hundreds of previous posts with similar symptoms but cannot nail down the problem I am having. I have an 06 F250 with an egr delete, cat delete, upgraded fuel reg spring, and SCT tuner.

Last year I installed an EGR delete kit, a new oil cooler and replaced the STC fitting. I was puking a bit of coolant whenever I towed my 10K trailer and I had some hard starting problems. None of these fixed my problems.

After I puked a gallon of coolant the last time I tried to pull my trailer, I decided to do the head gaskets and studs. I spent a couple weekends putting it all together.

After I got finished. It started up and ran normal after it worked a little air out of the system. I babied it around the neighborhood and noticed the turbo was farting a bit more than usual but figured it needed a little time to "relearn". I pulled it up to 55 with about 3/4 throttle and everything seemed fine until I heard it develop what sounded like an exhaust leak. As I pulled up to a light I noticed it was idling real rough.

I limped it back into my driveway and noticed it was puffing black smoke and running like it was on 7 cylinders. After it cooled down and I restarted it continued to idle rough and was pouring out grey smoke continuously.

I pulled up a #8 cylinder contribution code with AE and an EGR code because I was running it without the SCT tunes (stock only).

I decided to pull the #8 injector. Nothing found. I pulled 2, 4, and 6 as well. None of them showed anything remarkable.

After I did that, I realized I should have done the balloon test. I balloon tested the other bank and saw nothing.

I picked up some new o-rings today and a replacement injector from the dealer today and reinstalled only to have the exact same problem.

I am stumped. The AE shows a low contribution for #8. My IPR and ICP are reading normal ranges. Anyone have any ideas?

[J_D]

I talked to a Ford tech today and he diagnosed a couple of things to look at until I can get it over to him. He asked if it had uneven cranking like it would spin a little faster at one point. Mine does. He thought it could be a problem with a valve bridge not set correctly.
I am going to pull the valve cover and check tonight.

[PowerstrokeTech82787]

yeah its possible but you wouldnt hear a hiss youd hear a clatter like the 6.4s get. that or youd have broken rockers and bent pushrods.

[J_D]

I pulled the driver's side valve cover again and checked the valve train again. All the valve bridges, rockers, and push rods look to be in place. I pulled the exhaust side rocker on the #8. The push rod is perfectly straight. The valves are secure and I can not see any visible damage.
I guess the next step is to do a compression test on this side.
If I do not find anything I will do a visual inspection under the passenger side valve cover.