Hiss/Squeal exhaust break

[Trucker_Mike]

I've searched and only found this topic covering older models, so... Wondering if it's a similar issue with my '14 6.7 SLT DRW now at 375k mi. Yes I'm a hotshot transporter.

Here's how things transpired:
1: Started to hear a hissing sound (like a vacuum leak) while climbing a steep hill in BC Canada. The hiss goes away without load, otherwise no difference in performance.

2: Maybe a week later then get a whistling sound when the exhaust break is working only under heavy load (but not over revving). Nothing noted without any load.

3: Within another few days the whistle changes to a squeal, either with or without load. Item 1 still applies, and Active Airbox requires service message pops up, I have boost but feeling like a loss of power accelerating under load and a lot more downshifting than usual.

Engine codes:[TABLE="class: one, width: 800"]

U010c
Network - Network Communication - ISO/SAE Controlled


Description
Lost Communication With Turbocharger/Supercharger Control Module "A"

[/TABLE]
[TABLE="class: one, width: 800"]

P003a
Powertrain - Fuel and Air Metering - ISO/SAE Controlled


Description
Turbocharger/Supercharger Boost Control "A" Position Exceeded Learning Limit

[/TABLE]


What's giving up here, bolt, gasket, clamp, manifold, turbo assembly? I can't see a damn thing in there without tearing things apart!

TIA,
Mike

 

[Hoefler]

Charge air system has a leak, bad boot, or intercooler is leaking.

 

[truckmen]

Hello Mike,

Does it also happen when you are in Regen state?
Also, do you get exhaust fumes into the cab?

I am having what sounds like exactly the same issues. I've had this for quite a while. I also determined that the issue is causing exhaust fumes to enter the cab because the exhaust that is currently coming out of the tailpipe is almost breathable in comparison thanks to the damned DEF that is getting injected into the exhaust stream.

Have I done anything about it at my end?? No, but I sure will once I can get to the house. I am still 200 miles away fighting a failed throwout bearing and now dead batteries up in Houlton, Maine (but I digress).

Hopefully your (and my) problem might only be a high pressure tubing somewhere in the charged air system.

Ralph

 

[Bob4x4]

Charge air system has a leak, bad boot, or intercooler is leaking.

Possibly if there was no lost comm code. The turbo failure(control)may or may not be caused by the com failure.there has been a software update for the air box but there also may be an obstruction on the intake of the airbox

 

[mhstevens]

I also had an exhaust brake squeal/whistle. It came on whenever the exhaust brake kicked in, immediately stopped when the exhaust brake stopped. I thought (imagined?) a slight noise when accelerating, but couldn't quite say for sure it was happening. About 75k miles, took it to the dealer under extended warrantee and had it taken care of along with the recalls. I figured it was either a bad exhaust manifold or gasket, turns out it was the "Intake heater grid gasket leaking" along with "air horn gasket". I was skeptical, however the whistle is completely gone so that must have been it. As an added bonus, it was covered under the 5 year powertrain warrantee so I didn't even have to pay the deductible.

 

[truckmen]

I also had an exhaust break squeal/whistle. It came on whenever the exhaust break kicked in, immediately stopped when the exhaust break stopped. I thought (imagined?) a slight noise when accelerating, but couldn't quite say for sure it was happening. About 75k miles, took it to the dealer under extended warrantee and had it taken care of along with the recalls. I figured it was either a bad exhaust manifold or gasket, turns out it was the "Intake heater grid gasket leaking" along with "air horn gasket". I was skeptical, however the whistle is completely gone so that must have been it. As an added bonus, it was covered under the 5 year powertrain warrantee so I didn't even have to pay the deductible.

The Intake heater grid gasket??? Oh jeez, I'm going to have to learn about that component.

Ralph

 

[Bob4x4]

The Intake heater grid gasket??? Oh jeez, I'm going to have to learn about that component.

Ralph

No worries that is extremely rare on the 4th gens

 

[truckmen]

No worries that is extremely rare on the 4th gens

Okay, I'm going to look at the connections between the aftercooler and turbo. I apologize to the OP for stealing the thread but hopefully my plight will shed some light on the OP's.

I'm trying to understand the correlation between the exhaust fumes and the squealing/screeching sound; I think there is, as both issues started occurring at about the same time. At the moment, I'm still broken down (as I write this) here at the truckstop in Houlton with dead batteries. Calling AAA after I eat lunch.

Talk about a dilemma. I can't get into gear because I lost my throwout bearing. Now I can't start my truck because of the batteries. If I get my truck started, I won't be able to get into gear
but I can't start in gear because I'll probably run into the AAA truck. AGh!

Ralph

 

[Trucker_Mike]

Can't say whether it's during a Regen, but definitely always hisses on acceleration, and always squeals on deceleration (in full ex brake mode, with or without load).

No fumes noted, cab Co2 alarm hasn't sounded.

Good luck with your present dilemma!

 

[mpaulson]

I just had squeals under load and heavy exhaust braking as well, but no codes (maybe I got it dealt with before it got measurable by the ECM) It turned out to be a warped exhaust manifold.

 

[truckmen]

I just had squeals under load and heavy exhaust braking as well, but no codes (maybe I got it dealt with before it got measurable by the ECM) It turned out to be a warped exhaust manifold.

Okay,
I made it home and will be getting inside the shop by weekend's end. If we have the same problem, I'll share what I find and hopefully it'll help with your problem.

On an aside, what do you have for an in-cab CO2 sensor?

Ralph

 

[mpaulson]

I don't have an CO2 sensor. I could smell the raw exhaust occasionally though.

 

[truckmen]

I don't have an CO2 sensor. I could smell the raw exhaust occasionally though.

Hello mpaulson,

I was asking Trucker_Mike. He'd posted right before you did. Did you replace your exhaust manifold with an OEM or did you go aftermarket?

Ralph

 

[mpaulson]

Hello mpaulson,

I was asking Trucker_Mike. He'd posted right before you did. Did you replace your exhaust manifold with an OEM or did you go aftermarket?

Ralph

Warentee, OEM manifold.

 

[truckmen]

Just discovered,

I have the same issue as Mike, the OP. And, just discovered it's at the rear of the engine and is the exhaust manifold to head. Been having this issue for a long time. The guys who are doing my Turbo actuator replacement saw the soot around the back of the manifold. They tell me it's at least 15 hours of labor getting to this as it is one of the worst jobs on these trucks.

Questions:
Does anyone concur?
Has anyone attempted this exhaust gasket replacement themselves?
Is this something most people can do on their own?