species8472

From Ford's patent:

"... if it is determined that the cam or cam phaser is not stuck or sluggish, the strategy may be terminated at 1032. Subsequent to 1032, the strategy ends or alternatively returns to the start. If it is determined that the cam or cam phaser is near the hard stops, the strategy advances to 1034 where noise minimization actions near the hard stops are overridden (e.g. inhibited). Noise minimization actions may include actuating a locking mechanism in the cam actuation system..."

They know about the noise issue and try to minimize it.

lawndart

How about posting some screen shots of the modifiable parameters that make the noise go away? Or anything that shows it is entering a cleaning algorithm while timed with the rattle. Not quotes from patents. Show it.

elptxjc

For me, that issue is easy to ignore. First of all, it doesn't sound detrimental to the engine to me, and it only happens when cold (and with M1 0/30, I've only heard it once, without trying to duplicate it, of course). Second, many owners convinced dealers to replace all of those parts, and issue remained. Third, Ford hasn't upgraded those parts (presumably because they're not defective), so why just replace them with the same? Due to those 3 reasons, and the fact I have a lot of warranty left, it makes zero sense to me to even waste time going to a dealer for that. Granted, I'm just talking about the 'deceleration rattle', which is more of a ratcheting noise than a rattle. Some trucks make an awful but similar noise at start-up, which I'd definitely rate as abnormal. But the one duplicated by blipping the throttle while stopped I consider it normal, even if not pleasant or desirable. I didn't expect European refinement on a Ford truck, to my expectations were not high, fortunately . I don't like engine noises, but you have to be smart about them. Just hope they don't get worse ... but only 4,6xx miles so far. We'll see.

Nicklaus

Well, I tried to achive tht this morning. I scanned all VCT parameters while reproducing the noise (Drive, cold engine, release throttle). I compared the same graphs with the ones plotted without noise (Drive, hot engine, release throttle)

I Haven't been able to see a difference between the two. However, What I learned is that there is no VCT actions in neutral (was probably the case before in the previous software when rattle was heard in neutre, cold and hot engines)

species8472

Nope. None of those. Why would I spend time chasing down a non-issue?

Facts are:

1. TiVCT control solenoids require cleaning;

2. Ford has a patent on VCT solenoid cleaning and acknowledge noise issue and patented algorithms to minimize it;

3. Deceleration rattle is programmable. It can be programmed to occur in “N” or “D”. Full disclosure - I only have one data point (my truck) for this. But it confirms the decel rattle is a controller behaviour rather than uncontrolled malfunction; and

4. My oil analysis at 40,000 km shows nothing abnormal. Truck runs great and tows amazing. Ok, again this is only my one and only data point.

So why should I spend my time worrying about the decel rattle? My intent here is to share my findings and hopefully put others at ease. If you are dead set on this decel rattle being an issue, well, good luck and all the best.

BTW, as I have said else where, the startup rattle is another beast. It seems uncontrolled and should be look at by a shop.

lawndart

Of course it doesn't rattle in neutral.......there is no demand for cam movement in neutral, the VCT is locked. To say that means the rattle was intentionally designed in by Ford is supposition. Even Ford wouldn't knowingly release these engines loudly racheting. They certainly didn't know when the trucks started to make the noise. Without direct confirmation, VCT cleaning as the cause of the rattle is just one more plausible but unconfirmed guess in a handful of unconfirmed causes. It could even be a combination of factors.....low oil pressure, insufficient chain control, cleaning, poor VCT response all at once. Until someone fixes it we don't know.

Nicklaus

Interresting. Well, 2018 5.0 did rattle in neutral before the TSB which consists of a PCM reflash with a more updated software. After reflash, rattle in Drive only.

Confirmation of the root cause is exactly
what we all are looking for. This confirmation is unlikely to come from Ford (which would be ideal), so until then, I think it is still useful to share our thoughts on forum like this one and pursue constructive idea challenges in order to achieve a better picture of what is going with this odd noise.

Every topics discussed so far brought a piece of the puzzle and I personally enjoy this.

What I would really wish is that a Ford employee, aware of this noise and its root cause, comes forward and drop THE piece of information that we look for. I have no doubt about the liability concern for a move like this, but there are ways to do it cleanly without tracking (we’ve seen this before on this forum).

I agree with Species: startup rattle is an other beast (loose stretched chain, bad tensioners, etc).

species8472

Mine used to only rattle in “N” and never in “D” until the PCM got updated then it only rattles in “D” and not “N” anymore. Single data point it is but it tells me beyond a reasonable doubt that it is a programming behaviour and therefore it virtually eliminated all mechanical failure theories.

And when it is a normal behaviour there is no fix needed.

noclutch

This may have been covered at some point and simplistic, but if part of the rattle is related to VCT cleaning cycles and the noise is only noticed when the engine is cold, why couldn’t the cleaning cycles be programmed to not happen until after a certain temperature??

species8472

Good question. Let's for a moment assume with certainty the rattle is the side-effect of solenoid cleaning and Ford implemented it as described in the patent. The cleaning cycle determines whether it needs to run based on the time elapsed between a phase change command to the solenoid and the actually phase change on the phaser from the phase sensor. If the time is within a certain amount, cleaning will not occur. We all know oil flows more sluggish when cold. So it is conceivable that the cleaning subroutine is running all the time, just that the program sees that when the engine is warm, oil flowing happily, solenoid is not sluggish, and phase change response time is good, so no cleaning required.