Ok so some may know about this some may not but it is something that is coming on strong with many showings at dealerships across America. So as most know it is timing chains that are prematurely stretching causing this startup noise. The news is that there is updated parts out there to address this and Ford now has a TSB on this issue formally admitting to it being a common problem. I go over it all in this video. There is also a link to just how it sounds in the description of the video on youtube. Hopefully more dealers will be willing to dive into the engine with some guidance from Ford now.
Ford F150 3.5L Ecoboost Rattle Upon Start Up- Timing Chain Stretch Issues TSB
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makuloco2000
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You don't. You eventually just figure out how long to let it crank. Not enough time cranking, you get the rattle. Had to crank longer and longer as the chain stretched longer and longer. Hotter external temps = longer crank time. The longer it was parked the longer you had to crank it. There were times at the end when it sat for a day or more in 90 plus temps where I'd have to crank it 10+ seconds.
Lol
First, I'm really happy for you. It's awesome that you have a mechanic that knows what he's doing and showed you mercy as well!
And you might be right about me. But the jury is still out on the Gen2 and chain life. Who knows?
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Sorry mate, but what Yaw been doing lately doesn't count. That's chain abuse, plain and simple.
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I’m more so curious if there’s too much vacuum being put on the crankcase causing these issues.
Especially now that the pcv is designed to be open at high vacuum situations idle/deceleration. When you’re going down. a grade in full vacuum going 60mph, your intake manifold makes a crazy amount of vacuum.
Also on cold start the pcv is now wide open rather than restricting flow.
Crankcase vacuum does in-fact affect oil pressure....meaning the chain tensioners no longer tension. Now that the gen2 runs a lower oil pressure than the gen1s, that can most definitely cause issues if there is too much vacuum.
Tho just a theory....
Especially now that the pcv is designed to be open at high vacuum situations idle/deceleration. When you’re going down. a grade in full vacuum going 60mph, your intake manifold makes a crazy amount of vacuum.
Also on cold start the pcv is now wide open rather than restricting flow.
Crankcase vacuum does in-fact affect oil pressure....meaning the chain tensioners no longer tension. Now that the gen2 runs a lower oil pressure than the gen1s, that can most definitely cause issues if there is too much vacuum.
Tho just a theory....
Out of the millions of Gen2 now in the wild, there's still very very little news on worn timing chains. Certainly not the codes that accompany the excess valve timing. (beyond 60°)
However, the fleet is only 3 years old and so the average mileage is probably considerably low yet?
If it wasn't for the clacking phasers, the Gen2 wouldn't even be confused with the notorious Gen1 timing chain related reputation. (I bet there's some kicking the desks at Ford engineering over those dang phasers)
Still, it's early, I admit. But the redesign was a considerable address to the Gen1 chain design. At OEM power output, I still have hope that most trucks will not experience the issue at the lower mileage.
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However, the fleet is only 3 years old and so the average mileage is probably considerably low yet?
If it wasn't for the clacking phasers, the Gen2 wouldn't even be confused with the notorious Gen1 timing chain related reputation. (I bet there's some kicking the desks at Ford engineering over those dang phasers)
Still, it's early, I admit. But the redesign was a considerable address to the Gen1 chain design. At OEM power output, I still have hope that most trucks will not experience the issue at the lower mileage.
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You would need to study other manufacturers as well. Numerous OHC engines are known to "chain stretch"
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Great thought actually but not the case. Vac is important but it is kept in check by the pcv valve
Edit: pcv valve isn’t wide open. Do not mistake this for a simply one-way check valve. The PCV valve's internal plunger dynamically meters the appropriate amount of crankcase vent airflow based on current engine load. Proper PCV valves prevent the "vacuum leak" that a check valve would create at low loads.
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Speaking of the newer brown pcv valve, correct ?
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But see with the improved brown pcv, it now has a stiffer spring that keeps the valve open during idle and now during a part of decel. It will close at higher vacuum but not as quickly/frequent compared to the older original one. The original pcv closed immediately at idle/decel. I was able to pull up the patents for the valves a few days ago.
Edit: They changed the pcv to create a greater Venturi effect and keep the oil clean by having a constant vacuum on the crankcase( of course not when in boost).
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We use a custom pcv valve. We no longer use the brown one any longer and have better results. Unfortunately I can only have them made in -8, but soon to change to a -10 and or -12
However if used in a -6 it is better than the factory brown valve
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One wouldn’t be so concerned with pressure although critical, but there are somethings I’m sure poking around enough that you maybe able to think what will slow the rate of which the noise can start at compared to the mileage they typically do.
Anyone gets it prize if a lifetime
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After all my ranting over the Gen2 variable oil pressure system, I had an older fella, that is the go-to for "built Sprint Car motors" in our area for many years, hear my diatribe. (He's really my older brothers friend) So anyways, I noticed he didn't take the bait that I dangled, which I guess I was looking for some kind of confirmation of my disdain. Instead, he asked me how much oil pressure is the motor showing under load? I said ~70psi. He then asked how much at idle? I replied ~30psi. And then he asked if I had a sense of what triggered the high pressure request? I had to be honest and described that it only required a rather minor load demand to get it to jump.
His opinion was that although he understood my dislike for the complexity, that he felt like the oil pressure was plenty for a motor that had its bearings under load, as well as when they weren't under load. I think he was trying to get me to understand that I shouldn't be considering the mph of the truck as an issue. In other words, if cruising along at 70mph is really a relatively unloaded 2000 rpms, that 30psi was more than capable of supplying oil where needed. Basically I should relax. Lol
He had no problem with my disdain for auto stop/start though. Said he didn't care for the concept either.
Sooooooooooo, I'll shut up about the amount of oil pressure the Gen2 variable oil pressure system supplies, WHEN it is functioning as designed.
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His opinion was that although he understood my dislike for the complexity, that he felt like the oil pressure was plenty for a motor that had its bearings under load, as well as when they weren't under load. I think he was trying to get me to understand that I shouldn't be considering the mph of the truck as an issue. In other words, if cruising along at 70mph is really a relatively unloaded 2000 rpms, that 30psi was more than capable of supplying oil where needed. Basically I should relax. Lol
He had no problem with my disdain for auto stop/start though. Said he didn't care for the concept either.
Sooooooooooo, I'll shut up about the amount of oil pressure the Gen2 variable oil pressure system supplies, WHEN it is functioning as designed.
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