Black Sheep Ford

04' 5.4 has a loud rattle on cold starts. Also the timing is all off once up to temp and at low rpm. It has to be a tensioner right? I did the whole timing set 5 months ago and ran great. My first thought was tensioner seal hemorrhaging oil. I have just pulled off the timing cover and everything appears to be fine. I have changed the oil twice since this problem started. Motorcraft filter and 5/20 oil.
Any ideas?

primalurges

The start up rattle is definitely the chain tensioner. Why do you state that timing is off afterward up?

rubbinsracin

x2 on the chain causing the rattle. I fixed my chain rattle and most of my ticking at idle by stepping up to 10w30 oil. (i know, a whole different can of worms) I actually am planning on 10w40 on my next change, which is about 5k miles away.

I think the tensioner would have to be completely fail for it to allow the timing to jump. Does that sound right to everyone?

Black Sheep Ford

When at op temp it shudders and bucks at low rpm/below 800rpm. If I keep it feathered at 900 or above it goes away. Which lead me to believe bad tensioner blowing oil causing low pressure on top not allowing phasers to work.

primalurges

could be oil pressure loss just not sure if you could be losing enough through tensioner to cause to affect phaser to the point where it's causing rough idle. Have you checked oil pressure?

Black Sheep Ford

I opened her up and found my problem, a broken vain on pass. phaser and spring not holding on drivers! I would have bet it all on the tensioners but they were just fine. I tried to save money the first time and went with Dorman phasers. I'm becoming a pro at this so I just warrantied them and I'm sure I'll be doing it again. I put a new oil pump in this time. Why not!