[fharrison]

Anyone ever have an audible squel/modulating shrill sound when accelerating after truck has been running for a while? It is most noticeable on the highway when cruising and accelerating. Somewhere around 1500-2000 rpm. See attached video. I was extra careful while driving and recording.

https://drive.google.com/file/d/1HXXCVp0k10FMz0VyEGP71yDvVb8Cl_fk/view?usp=drivesdk

This sound is driving me nuts. I thought it was a vacuum leak so I replaced the 4x4 check valve and solenoid. This did not fix it. Let me know what you think.

 

[Jgleadle]

that's an odd sound, at first I thought turbo.. based on the high frequency but your boost/rpm's don't change..

 

[jmperlik]

@fharrison - can you tell whether the noise is coming from the interior or the exterior? (Sorry I can't tell from your video)

It reminds me of the fan going bad in my laptop, because it's definitely a sound coming from something cyclical, but the fact that it comes and goes (not constant) makes me think it is not coming from the engine bay. Try turning off all climate control (heat or air conditioning) to see if it goes away...

I agree (from just the 30 seconds of the video you posted) that this would also drive me nutso....

 

[fharrison]

@fharrison - can you tell whether the noise is coming from the interior or the exterior? (Sorry I can't tell from your video)

It reminds me of the fan going bad in my laptop, because it's definitely a sound coming from something cyclical, but the fact that it comes and goes (not constant) makes me think it is not coming from the engine bay. Try turning off all climate control (heat or air conditioning) to see if it goes away...

I agree (from just the 30 seconds of the video you posted) that this would also drive me nutso....

It's not very evident but the sound is only while accelerating. You can kind of see the rpms increase. When I let off the throttle, it stops. It is definitly coming from the engine bay. I can hear it with the window down. I also noticed recently that i can smell diesel exhaust briefly in the engine compartment when starting up. Wonder if this could be a cracked manifold causing the whistle/squeal. I just cant find any soot buildup but the manifold is mostly concealed.

 

[fharrison]

Also, it does not start making this sound right away. Only after the engine has been running for a while.

 

[jmperlik]

@fharrison - OK, should have gone back and read the title of your post after watching the video... So when it is "whining" is when you are stepping on the accelerator?

This is my first turbo, so I am no expert, but the turbo will spool up when you accelerate, so that would by my first guess (like @Jgleadle mentioned previously) Are you monitoring Turbo boost via FORScan PIDs or via the IPC (pretty sure there is a setting in there to make one of the small IPC gauges display Turbo Boost) not that we know what to be looking for (maybe loss of boost due to leak in turbo?)

The sound is definitely not normal -- I know you are probably tired of going to your dealer by now, but I think this is an easy one to recreate while taking the Service Manager hostage for a test ride, and let them diagnose & repair while under warranty.

I must say that you definitely have the record for these one-off issues that no one else is experiencing (DPF Piping, vacuum leak around turbo donut, etc.)

 

[fharrison]

@fharrison - OK, should have gone back and read the title of your post after watching the video... So when it is "whining" is when you are stepping on the accelerator?

This is my first turbo, so I am no expert, but the turbo will spool up when you accelerate, so that would by my first guess (like @Jgleadle mentioned previously) Are you monitoring Turbo boost via FORScan PIDs or via the IPC (pretty sure there is a setting in there to make one of the small IPC gauges display Turbo Boost) not that we know what to looking for (maybe loss of boost due to leak in turbo?)

The sound is definitely not normal -- I know you are probably tired of going to your dealer by now, but I think this is an easy one to recreate while taking the Service Manager hostage for a test ride, and let them diagnose & repair while under warranty.

I must say that you definitely have the record for these one-off issues that no one else is experiencing (DPF Piping, vacuum leak around turbo donut, etc.)

I am beginning to think I am cursed. I do love this truck though.

I did not think about turbo boost possibly leaking. I will check my connections and make sure they are tight tonight. The fresh burned diesel smell has me concerned since I do not have a delete, it should not smell like that, especially in the engine bay.

 

[BPS_PS]

Not that I am 10% sure this is correct.. but you may want to check the EGR components.. They have been know to crack from older vehicles from what I have read in the past... Again.. I am Parroting here... but hope you figure it out soon.. sounds like a trip to the dealer is eminent.

 

[Saathoff05]

@fharrison - OK, should have gone back and read the title of your post after watching the video... So when it is "whining" is when you are stepping on the accelerator?

This is my first turbo, so I am no expert, but the turbo will spool up when you accelerate, so that would by my first guess (like @Jgleadle mentioned previously) Are you monitoring Turbo boost via FORScan PIDs or via the IPC (pretty sure there is a setting in there to make one of the small IPC gauges display Turbo Boost) not that we know what to looking for (maybe loss of boost due to leak in turbo?)

The sound is definitely not normal -- I know you are probably tired of going to your dealer by now, but I think this is an easy one to recreate while taking the Service Manager hostage for a test ride, and let them diagnose & repair while under warranty.

I must say that you definitely have the record for these one-off issues that no one else is experiencing (DPF Piping, vacuum leak around turbo donut, etc.)

I am beginning to think I am cursed. I do love this truck though.

I did not think about turbo boost possibly leaking. I will check my connections and make sure they are tight tonight. The fresh burned diesel smell has me concerned since I do not have a delete, it should not smell like that, especially in the engine bay.

My previous truck was a 3.5 Ecoboost and did exactly what you are describing. It was a warped exhaust manifold which caused an exhaust leak. Traded the turd in for a 3.0 diesel!

 

[fharrison]

Issue should be solved. I crawled all over the engine and found the pipe connection from the exhaust manifold to the back of the egr had a stripped bolt. Must have been from a previous replacement. Found soot at the connection which was the telltale sign. I think the squeal was the leak through the gasket. Took it to the dealer and they found the egr is not repairable due to it being stripped. This will be my 4th egr replacement.

There is not much room to see around these engines. I was first concentrated on manifold to engine connection and there is just no way to see all 6 of those. From what I could see, they were clean. Glad I decided to get back far enough to see the back of the egr. It was obvious and the bolt just turned in place.

 

[jmperlik]

Issue should be solved. I crawled all over the engine and found the pipe connection from the exhaust manifold to the back of the egr had a stripped bolt. Must have been from a previous replacement. Found soot at the connection which was the telltale sign. I think the squeal was the leak through the gasket. Took it to the dealer and they found the egr is not repairable due to it being stripped. This will be my 4th egr replacement.

There is not much room to see around these engines. I was first concentrated on manifold to engine connection and there is just no way to see all 6 of those. From what I could see, they were clean. Glad I decided to get back far enough to see the back of the egr. It was obvious and the bolt just turned in place.

Nice investigation & find! Stripped hole in EGR ByPass valve? Hmm, I wonder how that happened?!? Hopefully they are replacing your EGR Bypass valve free-of-charge due to their incompetence?

With all of the exploding EcoDiesels (go read the EcoDiesel forums) due to faulty EGR ByPass valves leaking super-heated coolant into a plastic intake manifold and catching fire, knowingly stripping the bolt hole in your EGR ByPass valve and sending you back out on your way is pure negligence! Glad you found the issue and hope you give your dealership's Service Manager an earful....

 

[fharrison]

Issue should be solved. I crawled all over the engine and found the pipe connection from the exhaust manifold to the back of the egr had a stripped bolt. Must have been from a previous replacement. Found soot at the connection which was the telltale sign. I think the squeal was the leak through the gasket. Took it to the dealer and they found the egr is not repairable due to it being stripped. This will be my 4th egr replacement.

There is not much room to see around these engines. I was first concentrated on manifold to engine connection and there is just no way to see all 6 of those. From what I could see, they were clean. Glad I decided to get back far enough to see the back of the egr. It was obvious and the bolt just turned in place.

Nice investigation & find! Stripped hole in EGR ByPass valve? Hmm, I wonder how that happened?!? Hopefully they are replacing your EGR Bypass valve free-of-charge due to their incompetence?

With all of the exploding EcoDiesels (go read the EcoDiesel forums) due to faulty EGR ByPass valves leaking super-heated coolant into a plastic intake manifold and catching fire, knowingly stripping the bolt hole in your EGR ByPass valve and sending you back out on your way is pure negligence! Glad you found the issue and hope you give your dealership's Service Manager an earful....

I have to beleive the mechanic knew he stripped the bolt when he did. Maybe he did the "tighten till it turns easy and back off a quarter turn" method of torquing. Turns out other bolts were stripped on the unit. Had to replace the egr valve and cooler. Crossing my fingers it is good to go tomorrow.

 

[scott_nev]

I am having this exact problem that happened right after the EGR replacement, though the noise is louder than in your video and is absolutely infuriating to listen to while driving down the road. The dealer refuses to look at it and blows me off as "thats just how turbos sound". How did you convince them this is not a normal sound?

 

[Dunrollin]

Try a different dealer?

 

[jmperlik]

@scott_nev - first-things-first as I notice this is your first post, so let me be the first to welcome you to the forums!

Besides doing a visual/physical inspection to find a loose bolt along with the tell-tale soot around where it is leaking, I'm not sure much less will convince your dealer, as I doubt they will admit to stripping anything during either 18E02 or 20E04 EGR By-Pass valve recalls based on their initial response to you.

I assume it didn't sound like that prior to the EGR By-Pass valve recall and you complained to them very soon after noticing it was related to their recall work? Escalate to Service Manager and then to the GM to get some attention.

 

[navyR113]

Issue should be solved. I crawled all over the engine and found the pipe connection from the exhaust manifold to the back of the egr had a stripped bolt. Must have been from a previous replacement. Found soot at the connection which was the telltale sign. I think the squeal was the leak through the gasket. Took it to the dealer and they found the egr is not repairable due to it being stripped. This will be my 4th egr replacement.

There is not much room to see around these engines. I was first concentrated on manifold to engine connection and there is just no way to see all 6 of those. From what I could see, they were clean. Glad I decided to get back far enough to see the back of the egr. It was obvious and the bolt just turned in place.

The squeal sound from the gasket vibrating as the exhaust leaked past it would have been like when you were a kid and put a blade of grass between your fingers and blew through it!