Imgur gallery:
https://imgur.com/gallery/BgoxI
Story:
Engine did a weird stutter when I goosed the throttle under an overpass, and when I got it home it had a rattle / knock under the hood and threw a P0340 code. At 124k miles I wasn't altogether shocked that I may have lost a timing chain tensioner.
Shopping list:
- Ford Racing M-6004-A464 4.6L 4V timing chain kit, $455 at Summit
- OTC 6498 Ford V-8 Cam Tool, quantity 2, used from eBay
- Melling M227 oil pump, $86 at Advance
- Fel-Pro VS50477R cam cover gasket kit, $51 at AutoAnything (CSR price matched $38+s/h price found at Rockauto)
- Dayco PB1519N harmonic damper (not a harmonic balancer!), $59 at AutoAnything
- Dorman 620-120 radiator fan assembly with controller, $196 at Advance
Conclusions:
- The rattle/knock sound was just a cracked radiator cooling fan, thus the last item in the shopping list.
- The RH timing chain tensioner was bad and I believe the RH chain had skipped a tooth based on the fact that we had to slightly rotate the cam to get the timing marks lined up.
- The guides were still intact so I did not have to pull the oil pan.
- The OTC cam locking tools were helpful during gear nut removal and installation, and obviated the need to remove cam followers, but everything else in the kit was useless for this job. It's absurd that they don't sell the cam locking tool by itself. I'll be listing these back on eBay since I don't anticipate ever using them again.
- I was surprised to see the amount of varnish inside the engine, considering my exclusive use of Amsoil 5W-30 and Motorcraft FL-820S filters.
- Engine is running well again, so I think I avoided any valve interference. I would know right away, right?
- I think there is some contamination in the Autometer oil pressure sending unit because it reads zero unless the pressure is over 25psi. I'm trusting my low pressure alarm (Duralast PS103 and a piezo buzzer) will let me know if there is a critical low pressure situation.
Thanks:
- Blackened300A for the valve cover removal thread, and many other members who post detailed threads and responses here in Shop Talk!
- FordTechMakuloco for the oil pickup tube tip and many more videos.
- Mostly my wife for being my cheerleader, 2nd set of hands, and my cam cover cleanup crew.