Hi, I'm new here and have an unusual problem with my 2003 4.6 timing chains.
First, a bit about me. Age 64, retired heavy truck and equipment mechanic. I know my way around wrenches, but never worked on cars or light trucks.

Here's the situation: My 2003 F-150 with a 4.6 engine blew the gasket on the right timing chain tensioner and destroyed the upper right chain guide. The guide was crumbled to pieces when I pulled the front cover. I replaced everything. But when I started the truck up, the engine was still noisy. I tore it all down again and checked everything carefully. The right chain was not tight as it should be. Tensioner was fine, gasket ok, everything in place as it should be. Put it all back together again, but this time used Motorcraft tensioners. Double and triple checked everything to make sure it was right. But again when I started it, the chains were making a lot of noise.
Tore it down a third time. Right side chain is loose again. This time I noticed that the tensioner bolts didn't feel very tight when I went to remove them. They had been torqued to spec. So now I questioning my old torque wrench. Has it gone bad? Were the tensioners not tight enough to seal? ????
I put it all back together again. Triple checked everything again. This time I tightened the tensioners down tight. and checked the oil passages to make sure they were clear. DAMMIT! there's still a loud rattling noise in the engine!

What the hell is going on here? Is there other damage I'm not seeing? What should I be looking at? Has anybody ever heard of a problem like this?
For the record, I've always taken good care of my vehicles. Regular oil changes and inspections. The inside of this engine is completely clean.
HELP!

 

When the timing chain guides break the pieces fall down into the oil pan where they tend to clog the oil pump pickup tube. If this is what's happening in your case then you are not getting enough oil pressure to pump up the chain tensioners.

 

I figured it might be an oil pressure issue. However, the gauge reads normal. Unfortunately, I don't have the facilities or equipment to pull the engine. Does anybody know if I can get the oil pan off while it still in the truck?

 

Does this engine have cam phasers? they make noise when there on there way out as well. If you have oil pressure I suspect the pickup is ok.

 

No, it has just normal cam gears.

 

Just like alloro said most likely the pick up tube is getting clogged with chain guide debri.

 

I pulled the oil pan. There were some pieces in there and the pick-up screen was about half clogged with small stuff. I cleaned everything up and put it back together.
THE DAMNED NOISE IS STILL THERE!

I'm at my wits end. I've tried everything I can come up with. Anybody else have any suggestions?

I'm ready to sell this thing for whatever I can get and just be done with it.

 

Wow, I feel your pain. I've never worked on these modular engines so can't offer any input. But what comes to my mind is new, defective part(s)?

 

I did consider that. The second time I went into it, I put in Motorcraft tensioners. Can't do much better than that. Chains, gears, guides, etc all seem to be fine. Nothing visibly wrong with the cams or valves as far as I can see. I seems like the tensioners just won't pump up. I admit it. I'm completely lost.

 

 

Oh yeah, I did remove the clips.

 

 

Brand new chains, gears and guides.

 

The only other thing that I can think of is that the 4.6 has a check valve on the passenger side head towards the back that gets plugged up but not sure what year this was a problem, check into it.

Heres a video of what im talking about never personaly seen this problem.

 

Can we assume you used new gaskets under the timing chain tensioners and verified they have the necessary holes in them?