I know this thread went cold years ago but hoping that my reply may help others in need. I just went through converting my 99 Expedition 5.4 EB Edition from a remote oil filter location to a engine mounted filter. I searched numerous threads and never found a complete answer when researching my own problem. My model did not have the oil cooler unit on it but did have the two "oil cooler lines" that ran from the engine block all the way to the front of the vehicle where the "remote oil filter" location was.
My issue started with severe leaks coming from what looked like the metal crimps of the oil cooler hoses. I found a replacement Dorman set for about $130 online (some sets go for $100 but they do not include a tapped hole on the engine mounted side, the tapped hole is for an oil pressure sensor/switch if the vehicle is equipped with this which mine was). It took about 4 hours for me to remove the old lines and install the new ones. The biggest challenge in this job was on the oil filter side when physically disconnecting the lines from the oil filter mount. It's some type of a weird slip-fit between the mount of the oil cooler lines and the oil filter mount and I couldn't get them disconnected even after removing all the bolts. I ended up taking off three additional bolts to completely remove the oil filter mount completely and then I was able to pull the oil cooler lines off. Installing the lines went pretty smooth and I didn't run into many issues. Once I had everything put back together and topped the oil off I turned the key and TADA!....oil dumping all over my driveway.
The oil was coming from the engine block side but everything I looked at before turning the key looked tight and right. I ended up taking the lines back off and as I was doing this I found that the oil filter adapter casting that mounts to the block (in which the oil lines also mounts too) was cracked. My assumption is that this was a result of me tightening up the bolts on the oil cooler lines when I was re-assembling. I didn't put too much torque on the bolts (I was working with a 6" 10mm Combo wrench) but my guess is that over the years this casting became tempered and weak due to the constant hot/cold temperatures this part sees. Regardless, I had a bigger issue than what I started with.
Finding a replacement oil cooler adapter for the remote oil filter location is next to impossible. It is also very confusing when researching it because it seems like the part numbers are all very similar/same for the oil filter mount, oil adapter, and oil cooler. It turns out that the oil filter adapter on the engine mount side is a discontinued part according to other threads I read and also according to the Ford Dealership that I went to searching for this part. I went to a couple junk yards and had no luck finding a 5.4L Triton with this same adapter. My only option at this point was to convert my remote oil filter location to a block-mounted filter.
Through much searching I found the right parts needed which was the XL3Z-6881-AB Oil Filter Adapter and a F65Z-6840-A Adapter Gasket. I picked up both of these parts online for about $220. The Ford Dealer wanted over $275 for the Adapter itself not including the gasket. If you have the oil pressure sensor/switch you will also need either a 45 Degree fitting or a 90 degree fitting that would connect the Oil pressure sensor/switch to the oil filter adapter unit. This fitting is needed because the tapped hole for this switch in the Oil Filter Adapter makes it so there is interference with other parts of the car. I ended up using the 90 DEG elbow (with thread tape) and kicked the sensor at an angle where there would be no interference.
After putting this on I and topping off the fluids I was back in business.
A couple of tips if you are attempting this yourself...jack the vehicle up and get some jack stands under the front frame. Remove the driver side tire (there is some decent access to the oil cooler unit but you will end up needing to get under the car to get a shot at the bolts. You'll need a universal to get to 1 of the 4 bolts that hold the adapter to the block, the other 3 bolts you can get on without a universal. You will need about 10"-16" of extensions in order to reach the mounting bolts and to find a window where you have enough swing on the ratchet to break the bolts loose. You do not need to drain the oil completely out before starting but be prepared to catch about 1-2 quarts of oil when you break the oil cooler line connection. You will need to drain the radiator (catch the antifreeze in a clean bucket and reuse when complete) before you get started because there is a large rubber hose that connects to the oil adapter unit in which the antifreeze runs through. This hose will need to be removed from the unit in order to install the new adapter. The best way to access this hose and clamp is through the top of the vehicle. Open the hood and take the air filter off and push the large air duct out of the way. Look below that and you will see that you have a pretty straight shot to the clamp/hose. Buy both the 45 and 90 degree fitting before you start the job and just return the one you don't use. It's good to have both options to suit whichever condition you have. Also, for $13 you can replace the actual oil pressure sensor/switch. While I had everything off I ended up doing that too. After removing the original oil filter adapter from the block make sure to scrap off any remaining gasket to make sure you get a good fit with the new gasket/unit. When re-installing the 4 bolts once you have the gasket/new adapter on the block, make sure to pull it up evenly just like you would a tire. And for the love of God, do not over-tighten and crack the casting!!!
