02supercrew
Thread starter
Yeah this was my first fear and expectation when I bought it.I'd check the timing chain tensioners / guides / arms. The 2v mod motors love to idle and won't kill timing components if they're idling 24/7 .. like a police car or taxi.
What kills them is short tripping. Especially once they start to get older in age and the tensioners themselves start to bleed off. What happens is on a cold start, the tensioners have retracted and the chain slaps the tensioner arm. Eventually it will wear through and be riding on the piston. The noise you're hearing is probably chain slap. I had a weird top end sounding noise in the original engine on my 4.6 and turns out it was the tensioners and guides/arms worn completely down. My 5.4 had a bit of a rattle (not the piston slap) and it was bleeding off tensioners but nothing had worn through yet.
My 5.4 with 240K on it is VERY noisey on a cold start, but the harder it gets run the quieter it gets. I don't think the rest of the truck has enough miles left in it so I'm not entirely worried about it breaking a skirt or something. But the bores are very ovaled out - I discovered that when I had to change a head gasket.
It’s really not showing any signs of of needing a timing chain replacement . One of the first things I did after changing the crappy filter and getting the fuel pump going was to cut the serpentine belt and check it with a mechanic sthethscope. I went all over the engine, thinking it might be an exhaust leak, whole front end ect. The clatter if it happens now is always loudest on the top drivers valve cover between the 1st and second cop from the front towards the rear of the motor. Absolutely minimal or no apparent noise in the chain or guide area.
I could be wrong but the scope usually doesn’t lie on the sound.
No codes and fuel trims, O2 ect are right down the middle.