2013 Escalade noise: AC compressor or engine...?

[skpyle]

Good Afternoon, All!

My 2103 Escalade ESV is making a squeaking/chirping/scraping kind of noise from the engine compartment. It is low down towards the front.

This noise has been happening on and off for a few weeks. Sunday morning, I removed the serpentine belt, and ran the engine. No noise. I turned the idler pulleys, water pump, alternator, and power steering pump by hand. All were quiet except the power steering pump. It clicked some.
A-HA!

Reman power steering pump, GM seal kit, inline filter, and 2 quarts of synthetic power steering fluid later, the power steering pump had been replaced.
And the noise was still there.

I again removed the serpentine belt and ran the engine. Noise was still there. My next thought was 'AC compressor'. I turned on the AC, compressor clutch engaged. Noise did not change in any way shape or form.

I am now scared it is a noise from the engine.

I have ordered another stretchy AC belt. I will cut the existing belt off, see if the noise goes away.
If it does...will look at replacing AC compressor.
If it doesn't...


Here are three youtube videos I took, trying to capture the noise. Two are from above at the front of the engine compartment, the third is underneath. There is alot of background engine noise, but you can pick out the squeaking/chirping/scraping noise if you listen.

Sooooooo...please listen to these videos, see if you recognize this noise.


NOTE: Sunday, when I removed the serpentine belt to check for noise, the engine was at operating temperature. I had driven home from work. Today, when I removed the serpentine belt, the engine was cold started.

Thanks for your time!

 

[coluccim]

sounds like AC belt. Order the lisle tool (or copy) if you decide to change it (59560)

 

[skpyle]

Thanks!

I will pull the belt Friday after work.

Uh-oh…I think things have gotten ugly.

Listen to this youtube video:




I think a rocker arm is hammering on the driver’s side bank.
Looks like valve cover is coming off for a look see.

Yay.

 

[rdezs]

I'd go ahead and cut the compressor belt first, probably today, to either confirm or rule out the AC compressor. Assuming you have rotated the idler pulleys by hand to make sure they're not falling apart.

Difficult to diagnose sound across the internet.... But I agree, time to pull the valve covers and check for a rocker with a lot of slop to it. If it's not misfiring, kind of doubtful it's a stuck lifter. But it could be that you lost a trunnion bearing on a rocker. I wouldn't drive it until you get it properly figured out. Consequences could be expensive...

If all the rocker arms check out, time to pull the front cover and take a look at that timing chain tensioner that may have come apart on you.

 

[rdezs]

And how many miles are on this L94?

 

[skpyle]

I'd go ahead and cut the compressor belt first, probably today, to either confirm or rule out the AC compressor. Assuming you have rotated the idler pulleys by hand to make sure they're not falling apart.

Difficult to diagnose sound across the internet.... But I agree, time to pull the valve covers and check for a rocker with a lot of slop to it. If it's not misfiring, kind of doubtful it's a stuck lifter. But it could be that you lost a trunnion bearing on a rocker. I wouldn't drive it until you get it properly figured out. Consequences could be expensive...

If all the rocker arms check out, time to pull the front cover and take a look at that timing chain tensioner that may have come apart on you.

I plan to do that, thanks. I am off work again Friday. Will cut the AC belt and do a cold start.
I rotated both idler pulleys, alternator, and water pump by hand. All were smooth and quiet.
Good point about the rocker trunion.
No CEL, no misfiring felt, still runs like a top. AFM was tuned out by Blackbear in November of 2021, shortly after I got this Escalade, at around 123,000 miles. I cut the VLOM gaskets and blocked the oil supply to the VLOM in December of 2023, at 153,000 miles. I am hoping it is not a failed AFM lifter.

I am no longer driving my Escalade. I have secured another vehicle to drive to work and such. I will cold start the engine briefly after cutting the AC belt to listen for the noise. Other than that, I am not starting this L94 again until I figure out/fix what is wrong.

I am mentally falling down the rabbit hole of lifter replacement straight to full DOD elimination...


Thanks for the advice!

And how many miles are on this L94?

175,068 as of this afternoon.

 

[rdezs]

I would seriously plan on deleting the AFM components at this point. Since you already have the AFM tuned out by black bear, you can simply replace the lifters and slide in an OEM L92 camshaft. Steel plugs for the oil towers, followed by a flat valley pan. Replace the VVT actuator and solenoid, new timing chain, plug the oil pressure relief in the oil pan....Melling 10296 oil pump with the +10 PSI spring installed that it comes with. That's the bare basics, no need to spend a bunch of money on one of the pre-configured kits with God knows what sort of quality parts they give you. Get your LS7 lifters from Michigan motorsports, they are the real deal genuine Delphi with GM lifter trays. Felpro gasket set, I recommend the ARP head bolts.... Not the studs..... The bolts will set you back around $150 or so and are reusable.

Whatever else you want to do while you're in there depends on your budget. Like replacing the harmonic balancer, new AC Delco starter and or new water pump. You will need the crankshaft locking tool that bolts in place of the starter, readily available on Amazon. And a new crankshaft bolt. You can either go with the torque to yield which is cheaper, or spend a little more for the ARP bolt. Well the heads are off it's worth spending two or $300 to make sure they're flat, have them skimmed lightly, and at least get new valve guide seals installed. Trunnion bearing upgrade replacement is good as well.

I've done several between 150 and 200,000 miles. The cylinders in all looked excellent with the crosshatch still visible.

If you go the route with an aftermarket camshaft to get more power and do away with VVT, you will lose fuel mileage and low end torque usually, plus you will need black bear to retune the ECM. Depends on your intended use of the vehicle. The L92 camshaft is what was used on the 6.2s that didn't have AFM. You'll still have your 408 horsepower.

 

[j91z28d1]

Thanks!

I will pull the belt Friday after work.

Uh-oh…I think things have gotten ugly.

Listen to this youtube video:




I think a rocker arm is hammering on the driver’s side bank.
Looks like valve cover is coming off for a look see.

Yay.

that's pretty weird.. doesn't sound like ac co. compressor to me. probably just lock up long before that bad.

I think I'd pull the valve come and look for broken valve spring, or rocker coming apart

 

[swathdiver]

The first 3 videos sounded similar to worn idler and tensioner pulleys. All 3 of mine sounded similar at one time, not exact though.

And then you posted the 4th video! I think that something under the rocker cover needs fixing. Keep us posted on Friday when you get after it.

 

[rdezs]

I would definitely get it cheap stethoscope from harbor freight. Place it on each valve cover and listen. And then on the timing cover with the serpentine belt removed for safety. The AC compressor as well. The bellhousing. That should help quite a bit in deciding what to look at first. Sound travels in funny ways, so the stethoscope really helps.

You can do the same simply using any long object.... A wood stick about 18 in Long, like a piece of a broomstick, or an 18-in long piece of PVC. Stick one end against the valve cover, make a fist around the other end and put your ear up against your fist. You'll be amazed at what you hear.

 

[coluccim]

Thanks!

I will pull the belt Friday after work.

Uh-oh…I think things have gotten ugly.

Listen to this youtube video:




I think a rocker arm is hammering on the driver’s side bank.
Looks like valve cover is coming off for a look see.

Yay.

Was the last video cold start? Sounds way different than the first vid.

 

[skpyle]

I got up a little early this morning and removed the driver’s side valve cover.

I didn’t find anything obvious. No visibly damaged rocker arms, no tiny trunion needle bearings, no forbidden glitter, no broken valve springs, none of the rockers looked lower than any of the others.
All of the rockers had the same amount of slight side to side movement. I checked the ones that were tight from pushing valves open as I hand cranked the engine.

Using a ratcheting breaker bar on the crank bolt, I pulled the engine through a couple of rotations. I saw #1 cylinder intake and exhaust valves open and close.
Nothing looked wrong.

I rigged a remote starter switch and jumped the starter relay. Cranking the engine, compression sounded normal. All eight rocker arms on the driver’s side opened and closed the valves, all seemed to have the same range of motion.
I did not hear any banging/clanging/clicking/squeaking noise from the valve train while cranking.


Watch the youtube video below of the driver’s side valve train while cranking:

I loosely put the valve cover back on and came inside. Have to go to bed for work tonight.

Will be back at it Friday evening.

 

[skpyle]

Was the last video cold start? Sounds way different than the first vid.

The last video was the driver’s side valve cover, engine warm after driving.
It sounded different, and caught my attention.

 

[skpyle]

I have not been able to get back to my Escalade before today. Dealing with deferred maintenance on my wife's spare car, now my daily driver.

Today, I pulled the spark plugs on the driver's side. They have been in for just under 51,000 miles. All gaps were approximately 0.040". #2 was loose, as I did not have to break it loose, #8 was tight the entire way out.
Threads on all four plugs had a little light rust/crud on them. That disturbs me, because I had installed them with a light coat of nickel antiseize.
NOTE: I was planning to replace the spark plugs and wires at this 175,000 mile oil change anyway. It has been 50,000 miles.
Regardless.

Driver's side spark plugs: #2, #4, #6, #8. Note crud on body and hex of #2, and light rust/crud on all threads.

Tips don't look awful.

#2 spark plug hole. Staining makes me think it was loose enough to leak.

#4 spark plug hole. Plug was tight, no staining or implied leakage.




I ran a compression test on all driver's side cylinders. Blocked the throttle blade open and jumped the starter relay socket with a remote start switch:
#2: 195PSI
#4: 220PSI
#6: 195PSI
#8: 220PSI

Reason for compression test is that it is my understanding that a failed AFM lifter will cause low compression pressure. Looking at my numbers, they aren't low, but there is a noticeable spread. 25PSI between lowest and highest. 11% variation. Not awful, but concerning.

AFM cylinders are 1 & 7, and 4 & 6. So that doesn't explain my compression numbers either.

With the valve cover off, I rolled the engine over with the starter, and put my finger on the pushrod end of all eight rocker arms. I felt nothing 'odd' on any of them. Just the rockers moving up and down.

I borrowed the borescope from work, and looked in all driver's side cylinders. Because the camera tip was long and non-articulated, I could only see the inboard side of the cylinders and pistons. All looked good. Cylinder walls showed cross hatching and no scratches. Piston crowns did not have much carbon build up.
I could see part of each exhaust valve. They looked OK enough. Though what I would expect for 175,000 miles. If the heads come off, the valves are getting done.

Reason for borescoping is to try to rule out possibility of cracked piston crown. Supposedly that is a thing with 6.2L's and detonation. I don't think that would be a a problem for me. It got a Blackbear 93 octane tune less than a month after I bought it, and has ALWAYS had 93 octane fuel since I took delivery of her.
But, I had the means to check. So I did.

I will not lie, I naively thought #2 spark plug being loose 'could' cause the tapping sound I heard. I mean, a leaking exhaust manifold can sound like a rod knock. Sooo...
Yeah, I am an idiot.

I put everything back together so the engine could run. And it started making that squeaking/chirping/scraping noise as soon as it started. I got pissed, shut it off, and went in for the night.

I did not cut the AC belt yet, because I still have it stuck in my head that nothing changed when I turned the AC compressor on and off. Next round of testing, I will cut the belt.
Also, I will remove the serpentine belt again and do a cold start without it.

 

[skpyle]

#2 cylinder and piston. This is representative of all four cylinders and pistons on the driver's side.

A little closer to the piston. This is representative of all four cylinders and pistons on the driver's side.

#2 exhaust valve. Photo is blurrier than I thought. Sorry. Speckling on the face concerns me, but it is a 175,000 mile engine.
This is representative of all driver's side exhaust valves.

 

[skpyle]

Here is my plan now:

-remove serpentine belt, do cold start, listen for noise.
-if there is still a noise, cut the AC belt. Restart engine. Listen for noise.

I will be listening for the squeaking/chirping/scraping noise.
However, I want to let the engine run a bit to warm up. I will be careful because it will be quick with no water pump turning. I remember the sound turning into a tapping/hammering when the engine was warm.

Regardless of which noise I hear first, I now have a mechanic's stethoscope. I will start probing around the driver's side and front of the engine to try to pinpoint the noise.
Same if and when the tapping/hammering noise appears.


However, to be honest, I believe I am now facing diagnosing by disassembly. If it is a lifter and/or cam, head needs to come off. I will remove the intake and VLOM first, to look at what lobes I can see. Look for failed roller damage. Then pull the head.

If it is a broken timing chain tensioner, front of the engine has to come apart to get the timing cover off.


And here is my dilemma, and the cliff I am about to fall off. Whatever is wrong is going to require engine surgery and money spending to fix. How much is the question...

Do I just fix what is wrong? That will be the cheapest, and most time effective. Because this will take me time.
But, just pulling one head? Can't do a valve job then, because the other head won't match. Just replace the timing tensioner? Cam is right there...

However...to me, my Escalade is a keeper. I want to see at least 300,000 miles out of her. I am already building a war chest for a bulletproof transmission overhaul.
I am slowly talking myself into full DOD delete. Just get it over and be done with it. I am not there yet, but inching closer.

This weekend, I am on vacation. I was supposed to be preparing to road trip to Sterling VA next week for a Porsche 928 get together. That is gone now. My mode of high speed touring is down. I will spend this weekend taking things apart.

What I find will determine what I do next...

 

[skpyle]

And how many miles are on this L94?

Sorry I missed this. Odometer reads 175,068 at the time of failure.

 

[Geotrash]

Good Afternoon, All!

My 2103 Escalade ESV is making a squeaking/chirping/scraping kind of noise from the engine compartment. It is low down towards the front.

This noise has been happening on and off for a few weeks. Sunday morning, I removed the serpentine belt, and ran the engine. No noise. I turned the idler pulleys, water pump, alternator, and power steering pump by hand. All were quiet except the power steering pump. It clicked some.
A-HA!

Reman power steering pump, GM seal kit, inline filter, and 2 quarts of synthetic power steering fluid later, the power steering pump had been replaced.
And the noise was still there.

I again removed the serpentine belt and ran the engine. Noise was still there. My next thought was 'AC compressor'. I turned on the AC, compressor clutch engaged. Noise did not change in any way shape or form.

I am now scared it is a noise from the engine.

I have ordered another stretchy AC belt. I will cut the existing belt off, see if the noise goes away.
If it does...will look at replacing AC compressor.
If it doesn't...


Here are three youtube videos I took, trying to capture the noise. Two are from above at the front of the engine compartment, the third is underneath. There is alot of background engine noise, but you can pick out the squeaking/chirping/scraping noise if you listen.

Sooooooo...please listen to these videos, see if you recognize this noise.


NOTE: Sunday, when I removed the serpentine belt to check for noise, the engine was at operating temperature. I had driven home from work. Today, when I removed the serpentine belt, the engine was cold started.

Thanks for your time!

In my opinion, that noise is happening at 1/2 crankshaft rotation speed. I would lay money down (or at least a bottle of decent rye), that that's cam-related if you've ruled out a loose spark plug. A loose plug can produce an intermittent chugging/scraping sound like that. Timing chain tensioner? Maybe, but I'm not sold. Lifter that's loose in the plastic tray and twisting slightly? More likely. Lifter with a roller that's binding intermittently? More likely still.

I'm still happy with the Cam Motion Stage 2 Truck Cam in my 2012 L94. It's been running great for 4 years now, and the power it produces puts a smile on my face every time. Just pulled our Airstream with it over the mountains last weekend and it's effortless. You could go the L92 cam route as others have mentioned, but all I can say is I would do the same thing if I had it to do over again.

 

[Doubeleive]

you don't need to cut the ac belt the Lisle belt tool takes it off or puts it on.

 

[skpyle]

Found it. #5 cylinder intake non-AFM lifter roller is fragged.

I have not gotten a look at the cam lobe yet, but I am assuming it is ruined.

Will post full update later.

Full DOD delete is now beginning.