I'd say at this point the mechanic is off the hook, i wouldn't accept responsibility if i did the work. If you brought it back right after the work was done, that's one thing, but even though you thought there was still an issue, you decided to hook up your 5th wheel anyway and did more damage. Can't blame the mechanic for that.

Like others have said you're most likely looking at a new engine now.

 

Well she’s still running. Couple of updates. The flakes I thought were in the oil were actually in the oil catch pan that I used to change the oil, the problems I had pulling my fifth wheel actually were caused by a broken wire on one of the VVT solenoid connectors. The rough idle had seemed to be getting better but as the weather got colder I started to notice the temp gauge wasn’t going up past 1/4 and then I started getting low coolant temperature codes. I changed the thermostat and that brought the temp gauge back up to 1/2 but now it’s suddenly running worse than ever. It’s still fine up to operating temp but once it hits operating temp and the VVT solenoids kick in I have to drive like I’m in a high speed chase to keep it from shaking and idling rough and the smell of gas in the exhaust is making me sick not to mention sitting at the lights sounding like an old model T. I wish I never would have changed that thermostat and now I’m wondering if there is a way to bypass the temp sensor so it doesn’t kick the VVT sensors in

 

I didn't read back through all, though I have followed this from the beginning, but can't remember if you have tried this or not.

Try hooking up a scan tool and see what the O2 sensors are doing when hot. You may have a bad one that doesn't show up until the engine gets hot enough to let the O2 sensors control the fuel.

 

No, but you can lock the VVT phasers. Do a search on "5.4l cam phaser lockout kit" you will find many 4.6L/5.4L kits.

 

I haven’t tried the O2 sensor test. The driver side exhaust manifold has a pretty good crack in it and with the rich smelling exhaust that comes out of there when it’s running rough I’m betting the catalytic converters are getting pretty plugged. I have new manifolds but no time to change them. That’s why I was hoping for an easy way of locking the VVT solenoids like just removing the communication from the temp sensor to kick them in. I don’t have time to rip the motor apart to do a lockout kit. Wish I hadn’t changed the thermostat. There were days it never got above normal operating temp and it was nice not having the rough idle issue although I don’t know how great that is for the motor