3rd gear 4.5k+ rpm chirping sound

[peavey02]

Mine also does this. I'm at 16K miles now. It started at around 10k miles. It only happens after 4k RPM in 3rd gear.

I only run 93

 

[FordTechOne]

thanks for
Your input. The truck makes a metallic chirp about 5 times from 4500 rpm to the shift in 3rd gear. I’m going to setup a GoPro and try and track it down. Also going to data log 3rd and 4th gear. Any recommendations on what data I should record?

I’d monitor spark advance and O2S11 (bank 1 upstream) and O2S21 (bank 2 upstream) A/F ratio

 

[FordTechOne]

Mine also does this. I'm at 16K miles now. It started at around 10k miles. It only happens after 4k RPM in 3rd gear.

I only run 93

Does is also occur in 4WD?

 

[peavey02]

Does is also occur in 4WD?

I'm not sure. I never noticed it at the last RTO meet when I was in 4wd. (I was definitely beating on the truck to.) I only notice it on the street when I mash the skinny pedal.

Side note: I haven't noticed it since it warmed up. I'll stomp on it tomorrow during the day and see what happens.

 

[Antho]

did a few full runs this am. I noticed if i go through the gears and stay out of boost i dont hear it. So i did another run and as soon as i tip into boost it starts making the chirping noise. i've replaced the IWE check valve twice already but ill look into that also. Below are some observations but by no means do i know what i should expect with timing and AFR on a turbo vehicle. Nothing is really jumping out to me. I'm going to dig into the IWE.

3rd gear in boost
fuel starts at around 14.5:1 in both banks at 2k-4k rpm, once i get to 4200 rpm it drops to 12.8 bank 1 and 12.4 bank2 and gets down to 10.8:1 and 10.9:1 at 5500 rpm.

spark advance is around 13-14 degrees at around 2k rpm and starts pulling timing until around 4500rpm where it starts advancing again. Looks like its starts advancing again once the boost has stopped building and is holding

3rd gear no boost
when i did a run staying out of boost the AFR stayed at 14.6:1 on both banks and never dropped. also noticed the spark advance stayed around 18-19degrees

 

[Donmatteo]

I tested this morning as well. 9000 miles, 2019 4-19 build, 802A.

In sport, manual mode, 2H, 91 Octane, above 4.5K, I hear a chirping sound from the middle of dash area.

 

[GCATX]

I can't hear anything weird in your videos, though I don't have fancy speakers here.
I will say that when I romp on mine, I can hear what sounds like exhaust pulses hitting the back of the muffler/resonator, comes from under the truck. Seems normal to me.

 

[Antho]

Dug into the driver side iwe. Well, took it out. I noticed the hub side has some signs of grinding from not fully engaging. I did a vacuum test and it’s holding vacuum at 3 in hg. Going to go grab a new hub and iwe. The hub shows some signs of grinding as well. Maybe the front axle wasn’t seated properly with iwe or something. Who knows. I’ll report back.

 

[Antho]

Ok, swapped it all out and still makes the noise. Tried in 4A and couldn’t hear it but the driveline noise could be why I can’t hear it? Anyway, got back and pulled the vacuum lines off the iwes and kept in 2wd. Still makes the damn noise. So I don’t think it’s the iwe or vacuum.

 

[MudLovingFJ]

Great detective work, especially on something complicated like the iwe.

I’m 100% confident the noise we are all hearing is spark knock/pre detonation.
I’ve had iwe noise before on my last F150, this is absolutely not the same noise.