I have a 2003 Ford F-150 with a 5.4L 2VL Triton at 236K. The truck up to this point has been rock solid, with little issues mechanically. The first major repair I encountered was a leaking intake gasket and eventual blown head gasket (RS#1&2). I worked on the truck myself and made the following repairs: Completed the head job using a fel-pro head kit. I had the heads checked and shaved along with new valve seals. I also replaced the timing chains, sprockets, guides and tensioners. The guy who worked on the heads had a time with the lifters and had to soak them for a week to get them back up. I decided not to go into the bottom end as I have had no issues and the truck used very little oil before the repair. After the repair, I have put approximately 20K on the truck with no issues at all. However, the truck has recently developed a slight tick/knock after it reaches operating temperature. It is silent at startup and purrs like a kitten until it gets warm. There seems to be no issue with power and the truck runs fine with the knock, even on long trips. I would say that the knock has gotten a little louder over the past few months. I am at a loss as to the cause and would like to see if anyone else has any suggestions. My suspicions are as follows: 1. Maybe the tiny bolts on the timing chain guide have backed out (very low torque required) and are causing an issue with the chain slapping. 2. Maybe a valve train issue (lifters)

Morris

 

Morris...welcome
Did you have the oil pressure checked?? Not just from the dash...you'll need a good mechanical oil pressure gauge, so you get actual PSI readings.
my suspicion is that on cold start up oil pressure is fine...as it warms up it falls of quickly...so make sure that the oil pressure is checked both ways cold and warm idle.
Or did you replace the oil pump with the timing chains?

 

Thanks for the response! I did not replace the oil pump, but will check the cold and warm pressures to see if there's an issue. The dash gauge shows good pressure, but it could be faulty I guess. I'll let you know what I find. One other potential I've thought of is an exhaust leak.

 

I'd check real good for exhaust leaks. They can make knocking noise that is mistaken for internal engine sounds.

 

+1! Is the knock coming from the bottom end or top? Can it be heard on either side of the motor.

 

The dash gauge is an idiot gauge. It sits there in the middle unless the pressure drops below 8 psi.

 

To me it sounds like it's coming from the top left bank area. However, I can't say definitively that's where it's originating. I'm going to pick up a mechanic stethoscope this week and see if that helps to narrow it down. Thanks to all for the input.

 

All,
Sorry for slow inform, but I do finally have an update for the members. I purchased an oil pressure gauge and stethoscope to try and isolate the issue. The oil pressure checked out within specifications and the knock seemed to come mostly from the front left bank, as suspected. I removed the timing cover this weekend and quickly saw that the left bank lower timing chain guide was broken where secured by the top bolt. I have the replacement in hand and will work this weekend to replace. Thanks to all for your input. I have posted pictures for others to use as a reference. I have a video, but don’t know if they can be loaded to the site.

 

Find the broken part?

 

The broken part is the lower timing chain guide on the left bank. It's in the picture above with the plastic missing above the bolt.

 

Toyz was asking did you find the missing broken piece. A lot of times those broken pieces fall into the oil pan and get stopped up at the pickup.

 

Ok. I should have realized the actual question being asked. I did not see the broken piece, but need to look a little closer to be sure. If I don't see it, do you think it’s necessary to drop the oil pan and check for the piece\pieces? I assume so, but have never dropped the pan on this engine. I assume I’d have to lift the motor up some to do so. I would appreciate input from anyone. Thanks.

 

I would drop the pan for piece of mind, but I'll leave that question to the other engine guru's on here. Maybe they will see the pic and make the call.

 

yep +1 on dropping the pan and checking the oil pick up screen & make sure it is clean...and the pan for debris (the missing piece) as well as, anything out of the ordinary....like silvery /glittery particulates that might give a hint of oil starvation. Well as long as the oil pressure was in spec you shouldn't....just cover that peace of mind thing.

 

Ok. I replaced the guide this weekend and found the broken piece shown missing in the picture. Believe it or not, it ended up on top of the left head as shown in the new picture below. I did not see it before, because I removed the timing cover, without taking the valve covers off first. (I know, I have to take the cover off to reinstall the timing cover.) Long story short, I put everything back together and the truck ran great for a day. The following day, it when back to the original symptoms of ticking only when warm I assume it broke the guide again. My only guess now is the left tensioner is somehow defective. I'm contemplating changing out the whole set this time to be safe. Any thoughts?