These instructions should apply to any Fifth Generation Explorer or PIU with the 3.5L NA, 3.5L EcoBoost, or 3.7L NA. These may also be helpful for other models including Taurus and Flex that use a Cyclone or Ecoboost in a transverse configuration. If yours has the 2.0L, 2.3L or was produced beginning in 2020, this will not apply to you.
3.5/3.7 (for the Lincoln people) water pump/timing chain replacement procedure:
Raise vehicle enough to drain oil, reinstall drain plug finger tight (you'll be draining it again). Remove right front tire and inner fender well. Remove air intake hose, air box lid can stay or go as your preference. Remove the evap vapor line from the purge valve and the hard vapor line at the RF strut tower. Remove the fuel line from the fuel rail and the supply line at the RF strut tower (there is also an 8mm head bolt securing the fuel line to the timing cover). Remove the upper intake manifold, aka plenum (note there is a single 8mm head bolt securing the upper intake to a bracket that is semi-hidden under/behind the throttle body). Remove all 6 ignition coils, then LH and RH valve covers. Remove the oil feed rails and intake VCT solenoids (inboard on both heads).
Rotate the engine clockwise until both intake cam phasers are at 12 o'clock, install cam locks (you may have to slightly rock the cams with a wrench to get the locks to fully seat, this is normal). Drain and remove the degas bottle and hose. Remove the belt and belt tensioner (belt is easiest removed from the bottom, tensioner from the top). Remove the crankshaft bolt and pulley (a 3 jaw puller or 3 jaw harmonic balancer puller will work). Using your floor jack and a block of wood on the oil pan, jack up the engine to relieve tension on the engine mount, remove the engine mount. Remove all the bolts attaching the timing cover to the engine (don't forget the recessed 8mm head bolt adjacent to where the engine mount was), raising and lowering the engine as needed to get all the bolts out. Gently pry the timing cover free (it's RTV siliconed into place) and remove from the top (some people will recover the refrigerant and remove the AC line, but the job can be 100% done without it, the AC line is aluminum and will flex out of the way enough without damage). With the timing cover off you can inspect all your timing marks, primary chain and primary tensioner. Your timing marks are single dots located on each intake cam phaser and the crank sprocket. Their positions should be as stated, cams at 12 o'clock, crank at approximately 430. The primary timing chain should have colored links to match those timing dots on the sprockets. Two single links to match each cam and one double link to straddle the crank. If you cannot see the colored links, it's arts and crafts time! Mark each single link over the top of the cams and the double link straddling the crank. Inspect the primary timing chain tensioner, there are two different designs, but the rule is the same for both. There are teeth that mechanically lock the tensioner out, if 5 or more teeth are exposed, the primary timing chain is stretched and will require replacement.
After you've done your inspections and had your arts and crafts time if required, remove the primary chain tensioner, primary tensioner shoe (it's on a pivot), the long primary guide on the front side of the engine, and the short primary guide on the front side. Remove the timing chain (you have to twist it slightly to clear around the phasers). Use an 8mm wrench and reach in behind the Bank 1 (rear cylinder head) intake phaser and loosen, not remove the bolt holding the other short guide. Once you've loosened it and can pull the guide forward, stop.
Remove all the water pump bolts and slowly pull the water pump from the block, I say slowly because you are trying to allow the coolant remaining to drain into the oil pan and not sploosh all over the floor and make a huge mess. Once you're not draining coolant remove the water pump out from around the guide you left and reverse process to reinstall the new pump. To reset the timing tensioner, you'll need either a small straight pick or needle nose pliers, a paperclip, and a vise. The early design tensioners had a separate arm with the locking teeth, to unlock use the pick to disengage the mechanism and squish the tensioner closed with a vise, once completely squished, install the paperclip to keep the tensioner collapsed. The second design tensioners have the teeth made onto the plunger itself. To unlock it, squeeze the lock with needle nose while squishing in the vise, again locking it collapsed with a paperclip. Reinstall the short guide, long guide and the timing chain, placing the marked links to match with the dots, keep all slack on the chain on the tensioner side of the assembly. Install the tensioner shoe and primary tensioner.
Before pulling the pin verify all timing marks on both the chain and the sprockets match. As additional verification, there should be 48 links between each intake cam phaser and 35 links between the Bank 2 (front) phaser and the crank. If everything looks good, remove the pin from the tensioner and gently pry the tensioner out a little more to ensure good tension on the timing chain (oil pressure will do the rest once the engine is running).
Remove the cam locks and rotate the crank 2 revolutions until all your timing marks are back at the 12 and 430 positions. Verify timing by counting the links between positions, 48 between cams, 35 between Bank 2 and crank. As long as everything is ok, you won't need the cam locks again. If not, reinstall the cam locks, remove the tensioner, and retimed the engine until correct. Clean all the silicone from the block and timing cover, remove and replace the crank seal. Apply RTV to the timing cover and along the rear of the block as during installation you'll likely smear some off the timing cover (optionally you can apply all the silicone to the block side of things if you so desire). Reinstall all your timing cover bolts. Reinstall the engine mount and remove your jack from the engine. Drain the coolant out of the oil pan. The crank pulley can be reinstalled with a block of wood, a hammer, and dirty words, or you can purchase a crank pulley installer tool to press it back onto the crank. The pulley is fully seated when there is approximately a 1/8" gap between the end of the crank and the end of the pulley. Replace the crank bolt with a new one! Torque the new crank bolt to 74ft-lbs plus 90 degrees (its torque to yield, and therefore, one time use). From there you reinstall all remaining removed parts. Refill the engine with oil, change the oil filter and I initially fill the cooling system.
Cycle the key on (do not crank) to prime the fuel system and check for fuel leaks. Fully depress the accelerator pedal (this places the engine in clear-flood mode and will not fire the fuel injectors) and crank the engine over for 15ish seconds to rebuild oil pressure. Afterwards, start the engine normally, bleed any remaining air from the cooling system and check for leaks.
If you want to replace your cam phasers, secondary chains, and secondary tensioners, you'll remove the phasers with a TP55 (Torx Plus, but a standard T55 will fit just sloppily). The secondary tensioners are pushed into their notes and have no hardware to secure them. The phaser bolts are one-time use as they torque to 33ft-lb plus 90 degrees. The phasers are keyed to the cams and have timing marks that match to the secondary chains to ensure proper cam-to-cam timing. New secondary tensioners will stay collapsed until they are pushed fully in and released after being replaced, it's easiest to unlock them with a smack with a flathead screwdriver and a hammer after you've got your phasers and secondary chains reinstalled.
I hope this helps anyone that wants to tackle this one on their own. If you have any questions, by all means ask!
I would like this post to become a central hub for any owners considering performing this repair by themselves, and also to give insight to any owners that want to understand what their repair shop is doing.
