Salinger

Replaced my timing chain two weeks ago (15 hrs of work!) with EB at 80,000Km. As you can see, it was really time since the chain had jumped the cams/crank sprockets a few teeths. I expect that I was really close with a permanently dammaged engine/heads. The chain was 1/2'' longer in diameter than the new one, this is alot! They are 4 lines mark on the hydraulic chain tensionner and it was at the full 4 1/2 mark. Chain was loose on the crank sproket even with this tensionner spring loaded. New chain bring back tensionner at the second mark. When old chain removed, I noticed that the right CVT's had some loose and can be freely rotated a few degrees without any oil pressure into them. They made the same "ticking" sound that we can hear at start-up. I didn't changed the solenoids & CVT's cams because this rattle went gone since a while by changing oil at a more frequent period & with using OEM Ford oil filter. My issue was code P0016 related to the worn timing chain. Pictures below are with/without benders removed.

snobdds

That is a lot of stretch for a chain. It appears more and more people are coming to the conclusion the start up noise are the cam phasers. Keep us updated on the noise and the chain.

Cord

It has to be a mix of both. They replaced my passenger intake phaser and solenoid first and that didn't solve the error code. Tore the engine apart again and replaced the chain. Error code was gone, engine ran great and was silent. But, for only a week, then the rattle came back. Rattle has been there for 15 months now and it's getting dramatically worse and more frequent. However, my timing isn't all that far off. 2-3 degrees is the most the dealer has reported.

Salinger

I agree with this Cord,
I believe that a stretched timing chain is whipping the cams phasers at each start-up until oil pressure built-up in them. A non-linear velocity of this loose chain + absence of oil and pressure in the loose cams, may cause them to "rattle" when cranking the engine.
Since you still can have a "rattle" at start-up without a stretched chain and anymore P0016 code, this may explains that those cam phasers are bad because of their excessive loose.
On another taught, this may be a second cause if the cam phasers electric solenoid must not operate adequately without a regulated and constant oil pressure when cranking. Their schematics tell me that they are hydraulic piloted solenoid valves and if oil pressure isn't present and constant in them for the critical first seconds of the engine start-up, this may cause not to "servo" adequately the cam phasers (actuators), having them shifting from advance to retard (or the reverse), making them to rattle.
In conclusion: New cam phasers looks to better retain oil in them than old ones that go "dry" when sitting for a period of time.
Rattling at engine start-up may be a "cause to effect" of a worn timing chain whipping the cams phasers at each start-up, having them to worn prematurely AND the inadequate flow of oil pressure in the solenoid servos that disturb the phasers having them to hammer. All this, makes the harmonic vibration amplitude to increase in those phasers in time.
I would really appreciate been able reading about EB 2014+ new design. What are those new parts number that have replaced the critical old ones in this re-design?

Cord

It's a very interesting theory. Basically the slack chain takes out the phaser which now makes noise. Replacing the phaser solves the noise, but doesn't clear the code because the chain is also defective. The noise comes back a week later because only one of the phasers was replaced and the other one, already damaged, continues to get worse.

I'm going to start to push to see if I can't get them to replace the phasers under the repair warranty. Could be a long fight, but we'll see what happens...

Salinger

Good resume of your engine situation Cord, and good luck with your dealer!
Keep us updated..

olgzr

Subscribed

Viking1204

Yeah and it's been a nightmare every since. Seems they fixed the timing chain just fine but didn't put the Turbos back together very well, still trying to get that issue resolved, see thread below for more.


https://www.f150forum.com/f38/how-ca...nality-304946/

Joe45

Has anyone here heard of or experienced replacing the stretched chain with the updated AT4Z-6268-C timing chain only to have the "start up rattle" come back?

Salinger

Like you can see higher, we don't think that the chain alone is responsible for the "rattle" at start-up. Perhaps, new chain will transmit less vibration to the cams phasers that what we think, is causing the "rattle" at start-up. Those loose phasers don't seem to bother the dealer if they don't flag up any codes.
It may be a "normal" sign of wear for this EB design as they will "synchro" back the cams as soon as the oil pressure raise and regulate from the servo solenoids.
From what we can read from many EB forums and owners, only the full replacement of all 4 cams phasers will insure the absence of "rattling" at start-up. But still, some guys here have said that they experienced this "rattling" when starting some brand new EB in the dealer's yard, and who were sitting there since a while!
For myself, I still don't understand what parts (if any) was upgraded/redesign on the 2014+ EB that seems now to delete this "rattling"? Other than the new timing chain part number, all other parts looks like they have the exact same part code.
Time will tell... And maybe those 2014 owners will get into same club as we are when the'll reach 50-60k miles with their OEM 3,5L EB?