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So what's the deal with the 2K-rpm rattle?

dn1984

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since switching to 0w-20 the other day i've noticed the rattle is a lot quieter vs. 5w-30 to the point where i almost can't hear it. now, it could get stronger over time but so far so good, even though i don't care about the rattle. it's just an annoying sound
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GMONSTAH

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https://www.enginelabs.com/engine-tech/efi/how-does-dual-fuel-work-on-a-gen-3-coyote/

"How does the factory utilize port injection and direct injection? Is one just for idle?
Besides the emissions advantage of port injection at start-up, the intake valves stay clean from carbon buildup due to the fuel being sprayed across them at start-up. Once start-up is initiated, the clock is then activated and with coolant temperature rising, the direct injection begins to take over. This is a very smooth transition and is not noticeable at all unless you are datalogging it."
 

Vlad Soare

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I had to listen to the video three or four times to understand what we were talking about. I can barely hear it if I listen very carefully, and if I'm aware that I should hear something in that particular rev range. Frankly, I don't think it would bother me. It's just the way this engine happens to sound.
What would, however, bother me would be this one:



While the DI injector tick and the 2k rattle are consistent and don't sound particularly unnatural, this typewriter tick is a different matter. Someone who hears the DI tick or the 2k rattle might say: "hmmm, your engine does seem to be a bit noisy". Someone who hears the typewriter tick will say: "oh my God, your engine's broken!".
 

GT Pony

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Someone who hears the DI tick or the 2k rattle might say: "hmmm, your engine does seem to be a bit noisy". Someone who hears the typewriter tick will say: "oh my God, your engine's broken!".
Funny that Ford has a SSM (Special Service Message) to dealers that says the typewriter tick (aka BBQ tick) is normal, but Ford doesn't have a SSM that says the 2K-2.2K rattle is normal. Although, some (most?) dealers will just say the rattle is normal because after the typewriter tick SSM came out, any engine noise is "normal".
 
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Elp_jc

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Very interesting PI/DI article; thank you for posting it. That article makes the so-called '2K rattle' harder to explain as a PI/DI transition, since it can happen basically anywhere in the rev range. Now, the way most of us are experiencing it, is super light on the throttle, and starting at around 2.3K rpm. The question is: What percentage of engine load are we using there? It should be minimal. It can only start at 2,250 rpm at 40% engine load, which is where it starts in my car (and most others). But no way we're using that much load barely touching the throttle, so what is it then? At any rate, a test we could make is to give more sudden load to the engine when it starts to rattle, to see if it goes away.

As far as the 'typewriter click', it sounds awful indeed. And extremely hard to tell if it's rod-bearing knock or piston slap... but there are ways to tell :). Hope my engine doesn't do that, but at least right now, it doesn't. And that means my engine shouldn't have piston slap, or it'd be there since day 1. Therefore, if that noise starts later on, it has to be rod-bearing IMO. Besides, piston slap is much more prevalent when cold, meaning if it happens when hot, it must be awful when cold. Two of my Corvettes had it (LS1 and LS2 engines), but only for a fraction of a second during a cold weather cold start. The 'CLACK CLACK CLACK' noise is deafening inside the garage. So I personally don't buy that it's hot piston slap, when it doesn't have any cold piston slap; makes no sense to me.
 

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GT Pony

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^^^ Lots of people claim the BBQ Tick is oil cavitation in the journal bearings. I don't totally buy into that because if it was more cars on the road besides Fords would be ticking from oil cavitation. If it actually is oil cavitation, then there must be some very narrow parameters that need to be present to set it off. Plus, I highly doubt adding a little anti-friction modifier like Ceratec is going to change oil cavitation. I've always theorized the random BBQ Tick was set off by the friction lever between parts, like the rod big ends with the crank, and if the friction level is right the rod big ends can move side-to-side on the journal and cause ticking.

https://www.mustang6g.com/forums/threads/how-excessive-is-this-rod.108361/#post-2322748
 
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Elp_jc

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Just went for a quick drive to fill up my tank, but mostly to check my new oil temp gauge (works fine), and to pay attention to the stupid 2K rattle (with radio off). Damn, that thing is LOUD, even with the exhaust in sport. How come I didn't notice it before? It's all your freaking fault. Ha ha. And yes, it starts right at 2K, so the title is correct :D. And it lasts until 2,800 rpm. It's a BIG range. It started shifting where it starts as engine heated up, between 2,000 and 2,300 rpm. At least it was much less noticeable with the engine fully hot, to the point it didn't bother me. But I'm almost sure it does it in every gear, but it's hard to hear at higher speeds. Until someone puts a GoPro in the engine compartment, we won't know for sure. I opened the window, and could hardly hear it at operating temperature. So folks outside hearing our great V8 rumble in sport mode, won't be disappointed at the unflattering noises the wonderful Coyote can make when cold. Ha ha. But wonder how loud it'll be when I have to drive in quiet mode with my wife. Ha ha. I'll find out soon enough :). With engine cold, the rattle is almost embarrassing.

At this point, I just don't see what it could be other than the DI theory floated here, even when it doesn't make a lot of sense with the newly found warm fueling values. I tried giving the engine gas when it started making the rattling (once hot), and it immediately went away, so as little sense it makes, it's most likely the culprit. I don't think it's oil cavitation; the fact the rattling occurs hot or cold, meaning at a wide range of oil pressures, makes no sense to me. There's nothing else that can make that kind of noise that I can think of. I'm slightly disappointed that the noise doesn't go away, but since it's much less noticeable when hot, I can live with it :D. Curious what Mobil1 0/30 will do to the rattling. I'll find out soon enough :D.
 

NIXPP2

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since switching to 0w-20 the other day i've noticed the rattle is a lot quieter vs. 5w-30 to the point where i almost can't hear it. now, it could get stronger over time but so far so good, even though i don't care about the rattle. it's just an annoying sound
I just went back to 5w20 after several fills of 5w30, I am shocked at how much quieter it is now. When the motor was new, it seemed like the 5w30 was quieter.
 

ice445

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https://www.enginelabs.com/engine-tech/efi/how-does-dual-fuel-work-on-a-gen-3-coyote/

"How does the factory utilize port injection and direct injection? Is one just for idle?
Besides the emissions advantage of port injection at start-up, the intake valves stay clean from carbon buildup due to the fuel being sprayed across them at start-up. Once start-up is initiated, the clock is then activated and with coolant temperature rising, the direct injection begins to take over. This is a very smooth transition and is not noticeable at all unless you are datalogging it."
Thank you for that, shows that there's more variance than I thought with how the system blends together. But basically seems like at low engine loads it's mostly port injection, especially when cold, and when it's warm and under load it's mostly direct injection.

Just went for a quick drive to fill up my tank, but mostly to check my new oil temp gauge (works fine), and to pay attention to the stupid 2K rattle (with radio off). Damn, that thing is LOUD, even with the exhaust in sport. How come I didn't notice it before? It's all your freaking fault. Ha ha. And yes, it starts right at 2K, so the title is correct :D. And it lasts until 2,800 rpm. It's a BIG range. It started shifting where it starts as engine heated up, between 2,000 and 2,300 rpm. At least it was much less noticeable with the engine fully hot, to the point it didn't bother me. But I'm almost sure it does it in every gear, but it's hard to hear at higher speeds. Until someone puts a GoPro in the engine compartment, we won't know for sure. I opened the window, and could hardly hear it at operating temperature. So folks outside hearing our great V8 rumble in sport mode, won't be disappointed at the unflattering noises the wonderful Coyote can make when cold. Ha ha. But wonder how loud it'll be when I have to drive in quiet mode with my wife. Ha ha. I'll find out soon enough :). With engine cold, the rattle is almost embarrassing.

At this point, I just don't see what it could be other than the DI theory floated here, even when it doesn't make a lot of sense with the newly found warm fueling values. I tried giving the engine gas when it started making the rattling (once hot), and it immediately went away, so as little sense it makes, it's most likely the culprit. I don't think it's oil cavitation; the fact the rattling occurs hot or cold, meaning at a wide range of oil pressures, makes no sense to me. There's nothing else that can make that kind of noise that I can think of. I'm slightly disappointed that the noise doesn't go away, but since it's much less noticeable when hot, I can live with it :D. Curious what Mobil1 0/30 will do to the rattling. I'll find out soon enough :D.
Once you hear it you can't unhear it, haha. But pretty much every car does it. I think it's worth considering that even though the DI system isn't always active at light engine loads, the high pressure fuel pump is still mechanically driven no matter what. That's why I think it's just a resonance of the internal moving parts, especially since someone earlier said removing their sound tube made 80% of the noise go away.
 

Vstang2

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Thank you for that, shows that there's more variance than I thought with how the system blends together. But basically seems like at low engine loads it's mostly port injection, especially when cold, and when it's warm and under load it's mostly direct injection.



Once you hear it you can't unhear it, haha. But pretty much every car does it. I think it's worth considering that even though the DI system isn't always active at light engine loads, the high pressure fuel pump is still mechanically driven no matter what. That's why I think it's just a resonance of the internal moving parts, especially since someone earlier said removing their sound tube made 80% of the noise go away.
Yeah I have the 2k rattle as well and once I heard it I couldn't unhear it. I purchased a sound tube delete just to get rid of it tube but was pleasant surprised when the rattle was VERY must less noticeable. I can still produce it but it doesn't hammer away like it did before inside the cab and I only get a touch of it with the windows down and me listening for it.....it was quite load prior to the delete. For those that say the tube delete is unnoticeable I disagree as the rattle resonance diminished and my exaust/engine noise shifted to the back of the car where it belongs. Photo of me listening for the rattle lol
41fndGmp28L._AC_SX466_.jpg
 

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Elp_jc

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I think it's worth considering that even though the DI system isn't always active at light engine loads, the high pressure fuel pump is still mechanically driven no matter what.
That was an excellent point. Forgot the pump is mechanically driven; makes perfect sense. The DI system always has to have the proper pressure to take over when needed. The warm table seems irrelevant if the pump is making the noise, which now I believe it's probably the case.

We just need somebody brave enough to stuff a GoPro in there, to confirm :D. The best scenario would be to put it right next to the pump, and even remove the heavy rubber isolator on top of it. Then move the camera to the other side of the engine, where if the DI pump is the culprit, would yield a lower noise level.
 

ihc95

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We just need somebody brave enough to stuff a GoPro in there, to confirm :D.
I think you should do it, since you seem to be the only one advocating for this experiment lol. Do it for the community :like:
 
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Elp_jc

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I'd absolutely do it... but I don't own one of those dope things. Ha ha.
 

W.O.T. Stang

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My 2011 Manual and my 2019 Auto both have that same sound. I heard it first in my 2011 and thought it was transmission related, but when i got my 2019.. it had the same sound. Its not overly loud, but you can tell it's there.
Im not worried about it a bit.
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