In Reply to: Re: F150 4.6 saga continues posted by lonestarjeff on January 21, 2019 at 22:52:43:
Jeff, I'm coming in on the tail end of this so I will likely ask questions or make comments already discussed. With that said, these engines Only really had 3 basic issues. Broken exhaust manifold bolts, worn valve guides and timing chain noise. There is a hydraulic lifter/tensioner that tightened the chain automatically. Those would bleed down causing rattle on startup. Since you bought a chain kit, I'm guessing it came with a new one as well as the nylon tensioners. The scary part is that these are zero clearance engines. If the timing chain is off they will indeed bend valves. As I recall there are no timing marks to align the timing gears, cams etc. There was a tool that locked the cams in position and another that locked the crank. These were to be locked down prior to disassembly because very little movement was needed to get the cams and crank far enough out of position to bend a valve. A valve bent very slightly can cause a very light engine miss that may be interpreted as a rough idle and cause noise. I personally would do a compression test and or a leak down test to verify the valves are all sealing. By now You have likely figured out why shops generally don't want to attempt big repairs on high mileage engines. At some point its just cheaper to install a rebuilt unit and that likely costs more than the vehicle is worth. Feel free to email me or call me if you would like to speak in person.
Rocky in MO