2017 Lariat with70K mile. Engine knock at idle. Located knock with stethoscope at right side camshaft timing phasers. The 17 3.5 s different than earlier engines with 2 equal sized chains - one for each set of phasers to crank pulley. The right side engine (facing truck on left side) has the timing chain forward on the crank so the left side did not have to be removed. A Cloyes video states the timing cam lock tools were not needed. I had to buy them as I could see no way to hold the cams in place as the shaft lobes were not in a flat spot.

I found it helpful to mark the chain before removal to be sure I had the right spot on sprockets when reassembling as the guides will move the chain. Make note that the chain was drooping between phasers after installing the middle of engine chain guide. This was a concern as the cam holding tools locked the phasers. So I was wondering how to get the chain taunt. After installing the chain guide for the chain tensioner and releasing, the phaser rotated as it's spring loaded and the chain tightened up. There is no easy do-over when dealing with timing so I thought this will help someone who may be concerned about the chain droop.

I've read that the reason the phasers fail (knock) is because of low oil pressure. I wanted to be sure I had good oil circulation so I pulled the coil electrical connectors and turned the engine over for what seemed like 7-10 seconds before the oil pressure gauge came alive.

I was thrilled after engine RPM settled to idle that the knock was gone. I now have a completely normal quiet engine.

 

I may not be following from your post - but what part did you replace? The tensioners or phasers?

 

Timing chain phasers on right side of engine were replaced with new units. Reemployed the right chain tensioner and chain

 

Ok, thanks for sharing. Glad it is quiet! You replaced the original phaser or some that were already replaced under warranty / TSB?

Just my thoughts, but... If I have to take the front of the engine apart on my truck I would definitely replace both sets of phasers given the labor vs part cost and knowing they all eventually fail (of the original design).

 

I ordered the parts directly from Ford parts. They are the new version. The right side seems like the failure from my study.

 

F.Y.I. instead of removing all the coil connectors to keep your engine from starting, if you hold the accelerator to the floor before cranking, the engine will just crank, and won't start.