Constant ticking @ top of engine... lifter?

[Professor L Gee]

Well that's a curious development. Please do let us know what you find vis-a-vis oil in the engine when you get there.

Based on your video though, I agree with @donjetman's opinion about the probable causes:
1/ Stuck lifter
2/ Bent pushrod
3/ Bad/loose rocker bearing
4/ Exhaust leak on a single cylinder (per James)

A broken valve spring is a possibility also, but I would expect other sounds and problems to go with that. Usually (but not always), a broken valve spring = dropped valve.

The service manager said that the tech (who had left for the day) said that the engine was completely empty of oil per the dipstick. I went to check it myself, and the oil level was lower than full but still within the crosshatching on the dipstick. (Full disclosure: yesterday I had tried an oil additive method to get the lifter unstuck to no success, and I drained some oil so as to not overfill the crankcase. I brought the level back to within spec but not all the way to full.)

They told me that the piston rings were failing and that the bearings were bad and that oil was burning... but how would you get so specific without tearing the engine down, which they didn't do? And I wonder what they did when they were test-driving it... I myself haven't taken the engine above maybe 2000 RPM because the associated rattling (which sounds like a rocker) is very disconcerting to my ears. I'll need to get a video of that for you guys as well.

At any rate, I'm gonna take the truck somewhere else tomorrow afternoon. To their credit, they're not holding me hostage like I've seen in some of the horror stories from this forum.

 

[Geotrash]

The service manager said that the tech (who had left for the day) said that the engine was completely empty of oil per the dipstick. I went to check it myself, and the oil level was lower than full but still within the crosshatching on the dipstick. (Full disclosure: yesterday I had tried an oil additive method to get the lifter unstuck to no success, and I drained some oil so as to not overfill the crankcase. I brought the level back to within spec but not all the way to full.)

They told me that the piston rings were failing and that the bearings were bad and that oil was burning... but how would you get so specific without tearing the engine down, which they didn't do? And I wonder what they did when they were test-driving it... I myself haven't taken the engine above maybe 2000 RPM because the associated rattling (which sounds like a rocker) is very disconcerting to my ears. I'll need to get a video of that for you guys as well.

At any rate, I'm gonna take the truck somewhere else tomorrow afternoon. To their credit, they're not holding me hostage like I've seen in some of the horror stories from this forum.

If they performed a leak down test it would give them some info about the condition of the cylinders, but I didn't hear you say that they did that.

Best diagnosis at this point would be to remove both valve covers and look for looseness in any of the rockers.

Good luck and please do keep us posted with what you find.

 

[iamdub]

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:

Excuse the teenage text/tiktok speak, but that sounds "lifter af". Have you always ran full synthetic and performed oil changes regularly? If not, you could have some gunk built up and the high quality detergents in the HMFS oil began breaking down the gunk. A tiny piece could've gotten stuck in a lifter, keeping it from pumping up. I've seen this fixed by a few hard WOT runs to use the higher oil pressures to force its way in. Not suggesting you try this, but not not suggesting it, either. If the lifter has actually failed, it will need replacing.

 

[iamdub]

UPDATE:

Took the truck to the shop annnnnnnnnnnnnnnnnnd apparently my engine is shot and should be replaced. According to the shop owner, there's bottom-end wear as well besides the valvetrain noises.

Technically, they're not lying. But, a 184K-mile engine will have some bottom end wear. It gets wear the second it's started after being built.

"Shot and should be replaced"? You sure he was talking about your engine or him and his techs?

 

[iamdub]

The service manager said that the tech (who had left for the day) said that the engine was completely empty of oil per the dipstick. I went to check it myself, and the oil level was lower than full but still within the crosshatching on the dipstick. (Full disclosure: yesterday I had tried an oil additive method to get the lifter unstuck to no success, and I drained some oil so as to not overfill the crankcase. I brought the level back to within spec but not all the way to full.)

They told me that the piston rings were failing and that the bearings were bad and that oil was burning... but how would you get so specific without tearing the engine down, which they didn't do? And I wonder what they did when they were test-driving it... I myself haven't taken the engine above maybe 2000 RPM because the associated rattling (which sounds like a rocker) is very disconcerting to my ears. I'll need to get a video of that for you guys as well.

At any rate, I'm gonna take the truck somewhere else tomorrow afternoon. To their credit, they're not holding me hostage like I've seen in some of the horror stories from this forum.

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.

 

[Professor L Gee]

Excuse the teenage text/tiktok speak, but that sounds "lifter af". Have you always ran full synthetic and performed oil changes regularly? If not, you could have some gunk built up and the high quality detergents in the HMFS oil began breaking down the gunk. A tiny piece could've gotten stuck in a lifter, keeping it from pumping up. I've seen this fixed by a few hard WOT runs to use the higher oil pressures to force its way in. Not suggesting you try this, but not not suggesting it, either. If the lifter has actually failed, it will need replacing.

I bought the truck at high miles and have performed 2 oil changes in 9k miles of ownership, both times with full synthetic. Service records indicate that the oil was changed regularly before me, but I have no indication of which oil was used.

I had a dream of driving the Yukon to the next state over and the lifter noise magically disappearing. And I don't drive slow on the interstate either.

 

[Professor L Gee]

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.

That's why this whole thing didn't smell right to me, especially once I figured out that the truck was in their service for only a little over an hour...

 

[iamdub]

That's why this whole thing didn't smell right to me, especially once I figured out that the truck was in their service for only a little over an hour...

Busted. A proper/thorough compression test probably could be performed in an hour if you had eight techs, each with their own wrenches and compression testers. We all know this didn't happen. Shame on that shop.

Have you done any further investigating? I'll repeat @swathdiver's advice on getting a mechanic's stethoscope. Narrowing it down to a cylinder would be a first step in helping us to help you. The stethoscope is $5 at Harbor Freight and $6-$18 on Amazon. What's the most mechanically involved you're comfortable with performing?

 

[robgreg75]

Your tick sounds louder than mine but mine has made a ticking noise for a long time when under the hood which I was today (changing the radiator). Mine has 270K miles I don't even hear the ticking inside it even with windows down, only when I have the hood up. How pronounced is yours?

 

[Geotrash]

That's why this whole thing didn't smell right to me, especially once I figured out that the truck was in their service for only a little over an hour...

What's the latest, Doc?