6.2 chirp until fully warmed up, frequency follows RPM

[UmMerkur]

Hello everyone, first post here. Had a 2010 Suburban for a while but upgraded to a newer Denali.

 

Last week I purchased a 2017 Yukon XL Denali. When I bought it the engine sounded completely normal from cold to hot, direct injection ticks and all. The only thing not working was the power liftgate which I fixed in ten minutes.

It started making a rhythmic squeak or chirping sound that sounds like many of the videos I've seen of failed/failing lifters rubbing on a cam lobe. However, it completely goes away once the engine is fully warmed up, ie after 10-15 minutes of driving. No CEL, no vibration, runs great. Does not sound like anything serpentine belt or accessory related. Does not change whether AC on or off. Frequency follows RPM.

It can be heard from everywhere around the front of the vehicle, but under the hood it's loudest on the passenger side. It's just barely loud enough to hear in the cab with HVAC and radio off. I'm wondering if it's a gunked up oil passage, sticky lifter, an exhaust leak, rocker arm, or I suppose it could be a failing lifter. The dealership changed the oil a few weeks before I bought it. I haven't even put gas in it yet.
Worst case, I do have a warranty that covers the engine and internals. But I'm hoping it's something easy I can fix myself.

 

I'm might try the ATF in the oil trick to see if it's just gunk. And I'll take a good look to see if it's an exhaust leak.

Any ideas or tips?

 

Thanks!

 

Edit to add: oil pressure 40 PSI cold,~30 hot at idle.

 

Edit 2:

Video: https://www.youtube.com/watch?v=Oz_hsemg_kE

Just after starting, engine was cold.

Edited November 29, 2022 by UmMerkur

[newdude]

5 hours ago, UmMerkur said:

Hello everyone, first post here. Had a 2010 Suburban for a while but upgraded to a newer Denali.

 

Last week I purchased a 2017 Yukon XL Denali. When I bought it the engine sounded completely normal from cold to hot, direct injection ticks and all. The only thing not working was the power liftgate which I fixed in ten minutes.

It started making a rhythmic squeak or chirping sound that sounds like many of the videos I've seen of failed/failing lifters rubbing on a cam lobe. However, it completely goes away once the engine is fully warmed up, ie after 10-15 minutes of driving. No CEL, no vibration, runs great. Does not sound like anything serpentine belt or accessory related. Does not change whether AC on or off. Frequency follows RPM.

It can be heard from everywhere around the front of the vehicle, but under the hood it's loudest on the passenger side. It's just barely loud enough to hear in the cab with HVAC and radio off. I'm wondering if it's a gunked up oil passage, sticky lifter, an exhaust leak, rocker arm, or I suppose it could be a failing lifter. The dealership changed the oil a few weeks before I bought it. I haven't even put gas in it yet.
Worst case, I do have a warranty that covers the engine and internals. But I'm hoping it's something easy I can fix myself.

 

I'm going to try the ATF in the oil trick to see if it's just gunk. And I'll take a good look to see if it's an exhaust leak.

Any ideas or tips?

 

Thanks!

 

Edit to add: oil pressure 40 PSI cold,~30 hot at idle.

 

 

 

Any chance you can provide a video of the noise?  Uploaded to youtube then linked here is the easiest way.  

[UmMerkur]

On 11/22/2022 at 3:34 PM, newdude said:

 

 

 

Any chance you can provide a video of the noise?  Uploaded to youtube then linked here is the easiest way.  

Added a video to first post. I'll copy the link here: https://www.youtube.com/watch?v=Oz_hsemg_kE

Sorry for the delay, it's been a busy week.

 

 

Another update: it is not anything serpentine belt related, I removed the belt and the noise remained.
With a mechanics stethoscope (long screwdriver) the noise is loudest from the block, can't tell exactly where though. AC compressor and vacuum pump were quiet.

[newdude]

13 hours ago, UmMerkur said:

Added a video to first post. I'll copy the link here: https://www.youtube.com/watch?v=Oz_hsemg_kE

Sorry for the delay, it's been a busy week.

 

 

Another update: it is not anything serpentine belt related, I removed the belt and the noise remained.
With a mechanics stethoscope (long screwdriver) the noise is loudest from the block, can't tell exactly where though. AC compressor and vacuum pump were quiet.

 

 

Might be time to pull the head?  I'd start with the valve cover, check the valve springs see if any are broken.  Then I'd move on to pushrods and look for a bent one.  If you are lucky, its a bent rod and likely a bad AFM lifter.  Absolute worst case its a lifter eating into the camshaft.  

[UmMerkur]

5 hours ago, newdude said:

 

 

Might be time to pull the head?  I'd start with the valve cover, check the valve springs see if any are broken.  Then I'd move on to pushrods and look for a bent one.  If you are lucky, its a bent rod and likely a bad AFM lifter.  Absolute worst case its a lifter eating into the camshaft.  

If it's internal I'll just let the dealership deal with it. When I have some time I'm going to check the AC tensioner, vacuum pump again (in the video the noise seems to coincide with the pump pulley rotation), and check for loose bolts. It doesn't get any louder when the oil cap is removed, so I'm not sure if it's actually internal. Could be though.
If my attempts are fruitless, to the dealer it goes!

[GMCustomerService]

On 11/22/2022 at 11:24 AM, UmMerkur said:

Hello everyone, first post here. Had a 2010 Suburban for a while but upgraded to a newer Denali.

 

Last week I purchased a 2017 Yukon XL Denali. When I bought it the engine sounded completely normal from cold to hot, direct injection ticks and all. The only thing not working was the power liftgate which I fixed in ten minutes.

It started making a rhythmic squeak or chirping sound that sounds like many of the videos I've seen of failed/failing lifters rubbing on a cam lobe. However, it completely goes away once the engine is fully warmed up, ie after 10-15 minutes of driving. No CEL, no vibration, runs great. Does not sound like anything serpentine belt or accessory related. Does not change whether AC on or off. Frequency follows RPM.

It can be heard from everywhere around the front of the vehicle, but under the hood it's loudest on the passenger side. It's just barely loud enough to hear in the cab with HVAC and radio off. I'm wondering if it's a gunked up oil passage, sticky lifter, an exhaust leak, rocker arm, or I suppose it could be a failing lifter. The dealership changed the oil a few weeks before I bought it. I haven't even put gas in it yet.
Worst case, I do have a warranty that covers the engine and internals. But I'm hoping it's something easy I can fix myself.

 

I'm going to try the ATF in the oil trick to see if it's just gunk. And I'll take a good look to see if it's an exhaust leak.

Any ideas or tips?

 

Thanks!

 

Edit to add: oil pressure 40 PSI cold,~30 hot at idle.

 

Edit 2:

Video: https://www.youtube.com/watch?v=Oz_hsemg_kE

Just after starting, engine was cold.

This is certainly not what we like to hear, UmMerkur.  Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2017 Yukon XL Denali. To do so, please send an email to [email protected] with ATTN: UmMerkur/GM Trucks in the subject line.

Please include your contact information, VIN, a brief description of your concern, and the name of your preferred dealership. We look forward to hearing from you. To learn more about GM’s privacy policy, please visit https://www.gm.com/privacy-statement.html.
 
Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com
 

[UmMerkur]

6 hours ago, GMCustomerService said:

This is certainly not what we like to hear, UmMerkur.  Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2017 Yukon XL Denali. To do so, please send an email to [email protected] with ATTN: UmMerkur/GM Trucks in the subject line.

Please include your contact information, VIN, a brief description of your concern, and the name of your preferred dealership. We look forward to hearing from you. To learn more about GM’s privacy policy, please visit https://www.gm.com/privacy-statement.html.
 
Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com
 

I appreciate the offer, dunno if you'd be able to help since I'm outside of the factory warranty period.

I haven't checked the AC compressor belt theory yet, but at this point I think the noise may be internal.

[UmMerkur]

An interesting development: the techs at the dealership went looking for the noise and they say it's coming from the transmission. Two days ago it threw a P0700 code (generic TCM code) and when the tech scanned it, P0711 - temp sensor. I'm guessing bad transmission harness which I believe has the temp sensor integrated. Probably unrelated to the noise, just coincidental.

It sounded so much like a lifter rubbing on the cam shaft (noise was at half engine speed, ie cam shaft speed), even the service adviser and tech thought it was a lifter.

Unfortunately I have to leave it at the dealer to keep my place in line for the transmission tech, possibly two weeks... bummer. And they don't have any loaners.

 

Quick edit to add: the noise became more frequent and didn't always go away once hot. Some days it was quiet and only started chirping once it got some load on it and would come and go after that.

When I drove it to the dealer it was quiet until we started the engine again, and it was super obvious.

Edited December 3, 2022 by UmMerkur

[UmMerkur]

I figure I should add an update here for the poor guy that ends up here in 10 months wondering what happened.

 

They had another tech take a look who determined that the noise was indeed a lifter rubbing on the camshaft. Camshaft and lifters are being replaced, just waiting on a VLOM. It has enough miles that not replacing the VLOM is just asking for leaks. They are seemingly perpetually on backorder.

[UmMerkur]

A 'nothing happening' update: still waiting on a VLOM over a month later.

[newdude]

5 hours ago, UmMerkur said:

A 'nothing happening' update: still waiting on a VLOM over a month later.

 

 

Yea VLOM backorder is pretty poo right now.  Seen a few GM parts people in the parts department Facebook groups asking around for one and getting shot down.  

Edited January 27, 2023 by newdude

[UmMerkur]

1 hour ago, newdude said:

 

 

Yea VLOM backorder is pretty poo right now.  Seen a few GM parts people in the parts department Facebook groups asking around for one and getting shot down.  

One of the service advisors at the dealership said they've been getting some every 2-3 weeks, but the holidays likely disrupted that to a degree. They had all the other parts in stock or overnighted (lifters, camshaft, gaskets, etc.). They also had the parts to replace the transmission temperature sensor (the ol' P0711).

It is indeed poo, but what can you do? For now my Yukon is just chillin. I dunno if they opened a SPAC case, but I imagine that wouldn't help any if GM isn't releasing parts from the PDCs.

 

Edit to add: there are several other vehicles at the same dealership waiting on VLOMs.

Edited January 27, 2023 by UmMerkur

[UmMerkur]

Story time...

The parts guy found a VLOM through another dealer, no idea how, but he did. It was shipped to this other dealer who then decided nah, we keepin this fam, sucks to be you.

[UmMerkur]

Got a call Friday (the 17th) that my Yukon was ready to be picked up. "Huh?" was my response, last I had heard the part wasn't coming. It ended up turning up. Go figure.

 

#2 exhaust lifter failed and scored the camshaft, cam and all 16 lifters replaced.

Edited February 19, 2023 by UmMerkur