Cam Phaser/Engine Failure Reports

[smurfslayer]

Who knows, but for some reason, in my head, I see a phaser rocking back and forth or wiggling causing a rattle. Kinda like how a bad lifter sounds, but times 4. It doesn’t sound like a chain slap to me, but what do I know...

I don’t think you’d hear chain slap on a timing chain with excessive run out. The engine, quiet as it is, is too noisy and the tolerances we’re talking about are something like 3mm or so on a particular link to sprocket relationship. What you might notice is other noise incident to the crank / cam banks not being in a ‘precise’ enough time, but then, that sort of what phasers do, isn’t it?

 

[WraptorBoy]

Who knows, but for some reason, in my head, I see a phaser rocking back and forth or wiggling causing a rattle. Kinda like how a bad lifter sounds, but times 4. It doesn’t sound like a chain slap to me, but what do I know...


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Interesting.

In my head, I picture a slightly loose chain just rubbing against a guide at startup. Then, after a second or two, some pressure from some part in there builds up and the chain becomes taught again.

And I agree on the cam phasers. They do one thing: advance or retard the timing as needed. Not sure what they would have to do with a noise or why they would even be part of this issue. Maybe, as Crash45 believes, they furiously rock back and forth for a second until the pressure builds and settles them, hence that noise.

So to feel better, I'll do a search on "how many miles on your ecoboost" and I'll read 20 pages of "I have 80,000 miles on mine without any issues"

 

[WraptorBoy]

So after researching more on VVT and cam phasing, I understand more how they work and what they have to do with the noise.

Basic explanation for those interested: The cam phasers, under various conditions, will fill tiny veins with oil causing pressure at various points within the phaser. The pressure then releases (or compresses) a spring loaded plunger (about 3/8" in diameter). Once that plunger is released, the phaser can now rotate (thereby rotating the cam) a small number of degrees to allow advanced or retarded timing as needed.

Anyone who’s run a chain final drive motorcycle probably understands this.

This ia a good analogy but the chains should never stretch (beyond just the thing brand new chains may do upon first use). The only resistance the chains will encounter is the weight of the camshafts themselves and all the parts associated (like the resistance caused by the springs on the valves and rocker arms) when the camshaft turns. A motorcycle chain does the same thing yes, but that chain needs to pull the weight of the driver and the bike etc. whereas the chain used for the cams only needs to turn the camshafts with the added resistance of the lobes hitting against the valves etc etc.

Anyway, I can totally picture that phaser mechanism malfunctioning and causing the noise we hear. Oil filling in a tiny passage to compress a plunger? Yikes!!

 

[aalonso]

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[WraptorBoy]

So sure, that’s a possibility with either a defective batch of chains, or tensioners that don’t have enough movement to compensate, but... How exactly would the phasers cause the chains to stretch more or contribute to it? Eventually, all timing chains would end up in this condition given enough time. Anyone who’s run a chain final drive motorcycle probably understands this.

I’m thinking these would be separate issues, fixed under the “in for a penny, in for a pound” principle. Again, if there isn’t heavy run out for the mileage, it probably doesn’t make sense to swap out the chains under a warranty claim. Now, if the tech said the chains were stretched more than he thought he liked but couldn’t warranty them, I’d spring for new chains and be done.

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I've read that article on that "fix it" type site. It's conflicting and too general to me.

It's mixing a TSB fix for a defective part(s) with regular maintenance (oil changes).

If you change your oil religiously, you still need to apply the TSB. If you don't change your oil regularly, you still need to apply the TSB. Further, if I don't change my oil for 8K miles (as opposed to the recommended 5K) and the timing chain stretches... that's some pretty poor quality chain material. Do I really want this engine?

Also, if you read too heavily into this article on this type of web site, you will think it applies to all ecoboosts when it doesn't.

Like I said, too conflicting to me.

Not sure why the one item that keeps the engine running perfectly (and if that one item fails would destroy your engine) would be so fragile on a performance oriented vehicle like the Raptor.

Porsche has been doing twin turbos for 30+ years. Are all their engines failing?

Makes no sense to me.

 

[MnFlyer]

To be fair not all eco boost 3.5s are failing either. Even the ones with the rattle are not failing per se.


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[Crash45]

To be fair not all eco boost 3.5s are failing either. Even the ones with the rattle are not failing per se.


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I agree with that. I’ve said this a few times, but this thread is so long, that was prob 30 pages ago. My 2012 FX4 that had it rattled one time early in its life. I heard it and was like WTF was that? My buddy was there and asked me when I got a diesel. Didn’t do it again until around 60k miles. Then at 100k it went from once a year, to once a month, to once a week, to every day, then multiple times a day. Started getting much louder and longer. Felt like it was on the edge of failure when I traded it. So yes, I think it can go a pretty good while in some cases, but yes if you have it, it will eventually fail IMO. One could argue mine technically didn’t fail, but I think it was as close as one can get. If it fails, the failure is catastrophic. At the time I was told a fix would be $3500-$4, if it fails $10k-$12k. I think they pulled the motor back then to swap the phasers. My raptor has its cab off right now at ford, and that makes me feel weird...


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[Crash45]

Oh, and my service writer (who I do like) went from never heard of this before, to we have one ahead of you getting phasers.


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[Antho]

Got my truck back yesterday afternoon. I don’t even want to tell you how long it took as it may infuriate a few. Anyway, the noise is gone. The service tech could replicate it with short throttle blips and got it taken care of along with updating a few modules. I felt I should get it done before the warranty is up and I’ll be “pre priming” at start up as Ryan has stated should help.

 

[WraptorBoy]

Got my truck back yesterday afternoon. I don’t even want to tell you how long it took as it may infuriate a few. Anyway, the noise is gone. The service tech could replicate it with short throttle blips and got it taken care of along with updating a few modules. I felt I should get it done before the warranty is up and I’ll be “pre priming” at start up as Ryan has stated should help.

Wow. Thanks for sharing. What year is yours and how many miles?