Constant ticking @ top of engine... lifter?

[iamdub]

If I have to get into removing heads, I feel like I'd be out of my element. Anything before that should be fair game, if slow and steady.

We just might be able to convince you otherwise. We recently walked another member, @tomloans, through cracked head diagnostics and replacement. I don't recall his previous level of experience or confidence, but he did the damned thang.

That's all a mechanic's stethoscope costs? I should have had one yesterday...

Yes! They can prove invaluable in a number of instances.

 

[iamdub]

Slow and steady updates!

So I had some time off today as well as some newfound energy (had been fighting a sinus infection for days), and I decided to go in and see which lifter had let me down.

I took off the passenger-side valve cover first (an absolute pain on all fronts), because a few months ago I had gotten a P0306 when driving home through Tennessee. That side was solid all the way down.
Decided to go into the driver-side (SO much easier), and lo and behold, the intake side of #1 is floppy and loose. The other seven were solid.

We're traveling this weekend, so the truck is gonna sit without coils and valve covers for a few days. Good luck if someone tries to steal it out of my driveway.
My next task will be to figure out if that lifter is bad or just stuck. I found a guy on Youtube who has had success unsticking lifters, and for right now I figure it can't hurt to try. If it works, cool; if not, the extra work will have to be done anyway.

As a sidenote, I have a list of "while I'm in there" tasks now that I've taken a few things apart... replacing valve cover gaskets (looks like that job was coming due anyway because of 183k miles), inspecting the VLOM to see if there are any leaks or clogged passages/filters, and (unrelated) re-looming a few harnesses.

This is where I was gonna go based on your response to my questioning of your mechanical abilities. You took it upon yourself to narrow it down and, lucky you, it's on #1.

Speaking of the VLOM, they have a much upgraded version. I don't recall the changeover year, but I wanna say the 2011 would have it. If not, you might have an explanation and relatively easy repair. Or, replace the lifter and disable AFM. Your next step is to determine if it's just a collapsed lifter or anything worse, such as a turned lifter, which means your cam is chewed and you have no choice but to dive deep into your engine or pockets.

Mine would tick after a cold start (nothing nearly as bad as yours and not consistent) at around 160K and AFM would hang for too long when slowing down, causing it to feel like it was gonna stall. I had AFM disabled in the tune and continued with high quality full synthetic oil changes and the ticking was eliminated. It started to come back as I approached 200K, so I did a full delete as well as the mods in my sig. If yours is in otherwise great shape and has been properly maintained, that 183K isn't a concern. How'd it look under them valve covers? Happen to take any pics you can share?

And "LOL" at "while I'm in there tasks"...

 

[Meccanoble]

The important details...

11 Yukon XL Denali, 184k
Oil just changed a week ago @ 184k, Valvoline HMFS 5w30, Mobil1 filter; oil level was normal when I checked it
No CEL or misfires
Tapping sounds rougher under acceleration; engine sounds normal otherwise
Oil pressure gauge reading about 30 at idle

Best case scenario is that I bought a bad oil filter which is affecting oil delivery (Google diagnosis), but I'm prepared for anything. LMK what y'all think.

Video of the sound:

Interesting enough, the only time I had an oil issue of any sort (oil sensor bad) was when I used a Mobil 1 filter for the first and only time. I'm sure its not related but just interesting... I also sit around 30 idle.

 

[tomloans]

Unless that shop performed a PROPER compression and leak-down test and had the oil analyzed and/or they disassembled the lower end and mic'ed the parts, they're full of shit.

Even when oil analyzed, it doesn't necessarily mean you have an issue that requires engine replacement. Oil analysis with other symptoms can help you decipher. Like @iamdub mentioned, I did a complete cylinder head replacement (with Iamdubs help here and others as well). Before I did this, I sent the oil sample to confirm coolant in the oil as I saw what appears to be coolant on the head when I took the valve covers off ( hence cracked head at 202,500 miles) and there was foam gunk built up on the drivers side. But besides coolant, there was certain metals in the sample as well which they said is an indication of bad rod bearings and likely I would need to replace these as well. They said most people usually have to replace them when they have my kind of numbers? Well I think "most people" that replace them are being told by poor mechanics to replace them. In any case, I did not and my numbers in the oil sample are almost back to normal and I have put about 3000 miles on my news heads. Car runs better than ever really. So be cautious before you spend tons of money. Go slowly. I would strongly suggest two or three rapid oil changes of about 1000 miles each and see if this will clear things up. Also, I don't suggest this but if inclined via convincing of youtube videos and not me, you can run 6 ounces of Seafoam in your oil about 200 or 300 miles before an oil change. Then do an oil change. You could do this with a fresh oil change and then change the oil after 300 miles. You will be surprised how dark the oil has become. It really works in many opinions out there. Do this only at your own risk please. Here is an interesting video...

Again do this only at your own risk please!

Now I am going to get in big trouble.

 

[Professor L Gee]

If yours is in otherwise great shape and has been properly maintained, that 183K isn't a concern. How'd it look under them valve covers? Happen to take any pics you can share?

And "LOL" at "while I'm in there tasks"...

I'll check out the VLOM once I get in there regardless. I think I do have the updated one, after some more reading and comparing.

Valve cover pic, as requested, showing not-unexpected coating and varnishing. The passenger gasket looks halfway ok, but the driver-side one is cracked in a few places:

Interesting enough, the only time I had an oil issue of any sort (oil sensor bad) was when I used a Mobil 1 filter for the first and only time. I'm sure its not related but just interesting... I also sit around 30 idle.

It is weird how the Mobil 1 filter has been a source of tapping for some people... before this and on my Infiniti, I had had no issues with those filters at all.
I'll check the oil sensor filter at some point, as apparently that's also a source of oil starvation to the top end.

Even when oil analyzed, it doesn't necessarily mean you have an issue that requires engine replacement. Oil analysis with other symptoms can help you decipher. Like @iamdub mentioned, I did a complete cylinder head replacement (with Iamdubs help here and others as well). Before I did this, I sent the oil sample to confirm coolant in the oil as I saw what appears to be coolant on the head when I took the valve covers off ( hence cracked head at 202,500 miles) and there was foam gunk built up on the drivers side. But besides coolant, there was certain metals in the sample as well which they said is an indication of bad rod bearings and likely I would need to replace these as well. They said most people usually have to replace them when they have my kind of numbers? Well I think "most people" that replace them are being told by poor mechanics to replace them. In any case, I did not and my numbers in the oil sample are almost back to normal and I have put about 3000 miles on my news heads. Car runs better than ever really. So be cautious before you spend tons of money. Go slowly. I would strongly suggest two or three rapid oil changes of about 1000 miles each and see if this will clear things up. Also, I don't suggest this but if inclined via convincing of youtube videos and not me, you can run 6 ounces of Seafoam in your oil about 200 or 300 miles before an oil change. Then do an oil change. You could do this with a fresh oil change and then change the oil after 300 miles. You will be surprised how dark the oil has become. It really works in many opinions out there. Do this only at your own risk please. Here is an interesting video...

Again do this only at your own risk please!

Now I am going to get in big trouble.

I've seen those Seafoam vids, and in those videos sometimes it works and sometimes it doesn't. I'm not inclined to try it myself.
So did you ever check your bearings to see if they were shot?

 

[tomloans]

I'll check out the VLOM once I get in there regardless. I think I do have the updated one, after some more reading and comparing.

Valve cover pic, as requested, showing not-unexpected coating and varnishing. The passenger gasket looks halfway ok, but the driver-side one is cracked in a few places:
View attachment 374574




It is weird how the Mobil 1 filter has been a source of tapping for some people... before this and on my Infiniti, I had had no issues with those filters at all.
I'll check the oil sensor filter at some point, as apparently that's also a source of oil starvation to the top end.


I've seen those Seafoam vids, and in those videos sometimes it works and sometimes it doesn't. I'm not inclined to try it myself.
So did you ever check your bearings to see if they were shot?

No I haven't because I frankly don't care. I have no noise at all and if I start hearing big noise from the bottom end, I will probably just get a short block as the heads are all new and my system is all nearly new as well. But I drive it very kindly and plan on getting another 100k Miles from it. If I had realized sooner that I had water in my oil, it would have been good. But it is what it is and it does run really good now so I will post if it fails on me but again I am very hopeful. Incidentally, replacing the heads was a real job. It is no wonder mechanics want $4k to do it. On the other hand, I took my time and replaced everything including valley pan gasket, the sensors in the back. The grounds in the back. The injector rings. Ping sensors and followed GM instructions regarding the ring around the back sensor. Probably forgot something. I replace everything that was made of soft or plastic material or was a sensor.

 

[donjetman]

I would never but something in my engine to try and flush the gunk/crud out.

I would describe the gunk/crud in your valve cover, and thus everywhere in your engine, as bad or worse than average.

In Dec of 2018 I bought our Denali off a used car lot with 130k miles and no mx history. It was burning and leaking 1 qt of oil every 3000 miles. I have since figured out the why.
1) the design of the pvc system thats built into the original driver side valve cover was bad. GM came out with a new improved valve cover. GM # 12570427 for 2007-2008, and GM # 12642655 for 2009-2011. Read this GM technical service bulletin: https://f01.justanswer.com/ebrock63...il+Consumption,+MIL+ON,+Engine+Runs+Rough.pdf

The result of a not installing the new improved valve cover asap was that the engine began sucking oil from the valve cover and into the intake manifold and burning it, thus resulting in stuck rings. And a lack of crankcase vacuum caused the rear main seal to leak.

Engine has 175k miles today and doesn't consumer any oil.

Here's what my neglected engine valve cover (top one) and all my spark plugs looked like. It had never ticked, missed or thrown a code.

 

[donjetman]

Professor L Gee, based on the shape of the pvc inlet it appears you do have the updated driver side vc, lower of the two. But WOW they are a mess.

I cleaned those spark plugs in my media blast cabinet and ran them another 35k miles.

 

[Professor L Gee]

Professor L Gee, based on the shape of the pvc inlet it appears you do have the updated driver side vc, lower of the two. But WOW they are a mess.

I cleaned those spark plugs in my media blast cabinet and ran them another 35k miles.

Yeah, I noticed I had the updated design after referencing some pictures. I have a few days before the replacement gaskets arrive, so between now and then I'll see about cleaning them up. At the mileage the truck is at, I'm gonna chalk it up mostly to age.

I do know (or at least suspect heavily) that the plugs in mine are original. A new set of those is also on order.

 

[Ronnie t]

Always worth checking/double check manifolds, they all get to a point of air leak somewhere