My Uncle has a house in the Caribbean (I know, sucks to be me). He needed to upgrade the island car from a 4 place 1987 Suzuki because running back and forth to the airport to collect folks (like, my family of six) was getting to be a pain. He is a GM guy, but I convinced him to get the perfect vehicle: 2003 2wd Expedition with fold flat 3rd row, rear A/C, 4.6L engine. Found it this spring in NJ, 130k on the car, and a diagnosis of 'cam phaser problem' so we stole it at $1500. This car will get like 3k miles per year tops on it from here on out, so the idea was to beat it and fix it all summer long to get as reliable a car as we could to ship to the island (would cost $8k to get the same thing already there). Brought it home, installed a new coil on cylinder 1 and got rid of most of the codes. Still had fuel trim issues. After a bit of sleuthing, decided a timing chain job was in order, which we did last month (good call, all the plastic guides were trashed, oil pickup was full of pieces when we dropped the oil pan). That put us proper. Started working on putting the beast on a boat headed to the island. Then, today, big old knock started coming out of the passenger side front of the valve cover. While searching for videos that replicated the sound, stumbled across this video that proved to be the winner as far as finding our problem:


Pulled the passenger side valve cover, found the whole side to be really dry, so then, after seeing the above linked video, pulled the rear camshaft bearing cap. No restrictor in our installation, but there is a passage, and found a nice 1/8" round glob of RTV blocking it. Pulled out the blockage, reassembled all, and all is well, no more knock.

So, long story not so short, here is the question from my GM minded Uncle: He says on GM engines, it would take a failure of the oil filter to allow such a thing to happen (RTV getting from the oil pan pickup to the restrictor passage to starve the rockers of oil). Is the same true for a 4.6L engine? Not knowing, he wants to drop the oil pan again to clean stuff out of it and the pickup. Me, I say we found the issue and just roll with it, but I will only be a part time driver of the Expy.

Thanks in advance, 15 years of help here has saved me THOUSANDS of dollars which I have rolled right into new(er) Fords (and, okay, a couple of Audis ).

 

First off, a 2003 4.6 does not have a cam phaser. I'm sure you figured that out when you pulled the timing chains. The question, can the RTV get past the filter? No. Nothing larger than a 40 micron particle will go thru any oil filter unless it's a Fram and the end caps have come loose. Then no oil is being filtered. So if you are using a quality filter like Motorcraft, Purolator, etc. it did not go thru the filter. Taking the pan off again will buy you nothing. From your post, sounds like it's ready to go. I'd suggest driving it a few hundred miles before shipping it so if there are any other issues you find them here and not there.
1 micron = 1/1,000,000th of a meter. With perfect vision 40 microns is the smallest particle you can see. There are 25400 microns to an inch. Most quality oil filters will filter at 10-15 microns per single pass thru the media.

 

Thanks, here not there for problems is definitely better, it will get a few hundred miles locally, then many more when I take it south to load on the boat.

 

Usually when you find RTV blocking the cyl head oil restrictor the RTV is from the disassembly process. When someone removes the cam covers or front covers they peel or cut away the RTV at the specific points of application. A piece of that RTV will drop into an oil passage downstream/upstream however you view it, of the filter either in the cyl head, in the pickup tube or the block. It will find its way while traveling through the oil system to that restrictor and get stuck there starving the cyl head of oil then the lash adjuster loses pressure and pump and a noise is generated. The RTV came from the initial disassembly. The problem is did the lack of oil to the cams start a enough damage to the cam bearing surfaces that it may take some time to actually fail? One of the craziest things I have seen was a large carpenter ant was lodged in that restrictor and caused a complete engine failure. We determined that the ant probably crawled into one of the oil passages of either cyl head or block while those components were sitting in dunnage on the line waiting for assembly of the engine. Not much in terms of preventive action you can take to prevent something like that.