Identifying 2013 6.2 Tick (attached video)

[thefrey]

2013 Yukon Denali 6.2 199k. AFM not deleted. Intermittent tick. 15psi hot idle and maybe 22psi cruising at 1800psi. Fresh full synthetic 5w30 oil changed about 800 miles ago.

Yukon is new to me, I bought it at about 197k. Last owner said that they replaced the lifters at about 190k but who knows.

The tick is very intermittent. Can be heard sometimes when the engine is fully hot, but sometimes there is no noise. Tick sounds more prominent while near the wheel well(s). It seems to almost always happen when the engine is cold but is very much 50/50 when hot. I did a "warm" start today after truck had been sitting for an hour or two and didn't hear a tick on startup

What are the chances that it's an o-ring issue? I've heard that a bad oil pickup o-ring can sometimes cause a clatter. Not sure though. I'm also not sure if it sounds more like an exhaust leak or a mildly sticky lifter.

 

[swathdiver]

I can't really tell, sounds like a noisy injector to me. Get a long extension or mechanic's stethoscope. Stick one end in your ear and touch the other end to parts you suspect the noise is coming from. If you have long hair, get it out of the way of the accessories spinning 'round and 'round lest you scalp yourself!

Oil pressure is lower than normal. Probably too low for AFM to turn on.

 

[thefrey]

I can't really tell, sounds like a noisy injector to me. Get a long extension or mechanic's stethoscope. Stick one end in your ear and touch the other end to parts you suspect the noise is coming from. If you have long hair, get it out of the way of the accessories spinning 'round and 'round lest you scalp yourself!

Oil pressure is lower than normal. Probably too low for AFM to turn on.

Here's another video perspective from the passenger side wheel well

Yup, AFM won't activate when hot. It does when it's cold though with the higher PSIs. Not sure if the AFM not activating would affect any lifter tick

On another note, found 1 stud broke, a couple missing bolts, and a bolt halfway out on the manifold. So maybe that could be something as well

 

[donjetman]

@thefrey
Sounds like a valve train issue to me.
Could be:
loose/worn rocker arm
lifter preload incorrect
bent push rod
broken valve spring

 

[thefrey]

@thefrey
Sounds like a valve train issue to me.
Could be:
loose/worn rocker arm
lifter preload incorrect
bent push rod
broken valve spring

I haven’t had the privilege of getting this deep into an engine before lol. What’s the best way to diagnose something like this? Should I start by taking the valve cover off and observing from there?

Also is a collapsed lifter out of the question here? Not exactly sure if the noise could be a lifter issue

 

[j91z28d1]

Here's another video perspective from the passenger side wheel well

Yup, AFM won't activate when hot. It does when it's cold though with the higher PSIs. Not sure if the AFM not activating would affect any lifter tick

On another note, found 1 stud broke, a couple missing bolts, and a bolt halfway out on the manifold. So maybe that could be something as well

fix all the broke bolts first.

 

[swathdiver]

Here's another video perspective from the passenger side wheel well

Yup, AFM won't activate when hot. It does when it's cold though with the higher PSIs. Not sure if the AFM not activating would affect any lifter tick

On another note, found 1 stud broke, a couple missing bolts, and a bolt halfway out on the manifold. So maybe that could be something as well

Whether it's an exhaust leak from all the broken bolts or a broken valve spring, I don't think any of those has anything to do with low oil pressure.

I'm chasing low oil pressure and a related leak right now. Lose too much oil and the pressure drops. Another day of rain and then I can get after it hopefully.

 

[rdezs]

It does sound mechanical in nature to me . ... A stethoscope would confirm a mechanical noise under the valve cover or under the engine valley cover.

Assuming you clearly hear a mechanical sound in the engine, I'd pull off the passenger side valve cover and check the trunions, as well as rotating the engine over by hand and checking for a push rod that is extremely loose indicating a collapsed lifter. And definitely fix the broken or missing bolts in the manifold.

A 2 ft long stick works great as a stethoscope. Even a wood broom handle cut off. Grab one end with your fist and put it against your ear and the other end against different components. You'll be surprised what you can hear. Keep long hair and loose clothing away from the belts....

 

[rdezs]

.... And while that oil pressure is on the low side, it's still well above with GM says is okay. I don't think that's low enough to cause any lifter noise..... But it wouldn't hurt to confirm the oil pressure readings with the mechanical gauge.

 

[thefrey]

Whether it's an exhaust leak from all the broken bolts or a broken valve spring, I don't think any of those has anything to do with low oil pressure.

I'm chasing low oil pressure and a related leak right now. Lose too much oil and the pressure drops. Another day of rain and then I can get after it hopefully.

Speaking of leak - have you noticed any oil pressure drop with oil leaking? I have a couple of leaks from the oil cooler lines that need to get swapped.

 

[swathdiver]

Speaking of leak - have you noticed any oil pressure drop with oil leaking? I have a couple of leaks from the oil cooler lines that need to get swapped.

I think it is. However, we put a lot of hours on the truck this week (21+) and the oil pressure was normal. Going to get it up on a lift and pinpoint the oil leak tomorrow.

 

[ilikemikes]

I just got all these same symptoms on my 2011 Tahoe 5.3 was about to get on the forum and ask the exact same questions. Recently had the exhaust manifolds redone and I was going to start by checking the bolts. At cold start it sounds like an exhaust leak, warms up and then doesn't sound like exhaust leak, then ticking for a bit then that goes away. My neighbor ex-mechanic thinks its a lifter and recommending pulling the oil filter and checking for shavings. Suggested cutting the filter in half but I'm thinking this would cause shavings to appear. I was traveling yesterday at 73 mph and my oil pressure was at about 28 psi. If I recall correctly, seems like I've always had a steady 40psi.

 

[j91z28d1]

I just got all these same symptoms on my 2011 Tahoe 5.3 was about to get on the forum and ask the exact same questions. Recently had the exhaust manifolds redone and I was going to start by checking the bolts. At cold start it sounds like an exhaust leak, warms up and then doesn't sound like exhaust leak, then ticking for a bit then that goes away. My neighbor ex-mechanic thinks its a lifter and recommending pulling the oil filter and checking for shavings. Suggested cutting the filter in half but I'm thinking this would cause shavings to appear. I was traveling yesterday at 73 mph and my oil pressure was at about 28 psi. If I recall correctly, seems like I've always had a steady 40psi.

if he's an mechanic, ask if he has the filter cutter. you're right that cutting them open without the tool is hard and can leave a bunch of debris that makes it hard to see. the right tool just pops the top off cleanly. still a messy job thou.


lifter is pretty common on these. check your bolts are all there and since you had work done, maybe check they are tight. but carefully. tq spec is pretty low.

is afm still active? how many miles on it and how often do you change oil.

 

[ilikemikes]

My transmission guy turned AFM off while tuning the transmission. Just changed my oil (typically through the % gauge). I am at about 185k miles. I measured the miles vs % gauge this time and was about 8500 miles with full synthetic.

 

[j91z28d1]

you're definitely in that range if lifters. the random rule of thumb around here seems to be 130-150k when oil isn't changed every 3-5k. of course some go 200k some 80k. it's all very random. kinda like the low oil pressure. it just hits

any idea what mileage he turned afm off?

 

[ilikemikes]

you're definitely in that range if lifters. the random rule of thumb around here seems to be 130-150k when oil isn't changed every 3-5k. of course some go 200k some 80k. it's all very random. kinda like the low oil pressure. it just hits

any idea what mileage he turned afm off?

Yeah, November last year so maybe 1500 miles ago. Any idea what the lifter job costs? Can I do it via youtube vids? TIA

 

[j91z28d1]

Yeah, November last year so maybe 1500 miles ago. Any idea what the lifter job costs? Can I do it via youtube vids? TIA

tons of info here and on YouTube. almost everyone regular here has done a delete kit. it's a bit involved but most people are about to make it work.

double check that exhaust before diving in thou

 

[ilikemikes]

Found 3 bolts loose on drivers side exhaust manifold. Much quieter now BUT now I'm tuned into the ticking in the engine. Probably time to get the lifters done. Thanks for all the help and "thefray", I didn't mean to invade on your thread and I hope you find a resolve.

 

[thefrey]

It does sound mechanical in nature to me . ... A stethoscope would confirm a mechanical noise under the valve cover or under the engine valley cover.

Assuming you clearly hear a mechanical sound in the engine, I'd pull off the passenger side valve cover and check the trunions, as well as rotating the engine over by hand and checking for a push rod that is extremely loose indicating a collapsed lifter. And definitely fix the broken or missing bolts in the manifold.

A 2 ft long stick works great as a stethoscope. Even a wood broom handle cut off. Grab one end with your fist and put it against your ear and the other end against different components. You'll be surprised what you can hear. Keep long hair and loose clothing away from the belts....

So i did the DIY stethoscope and it sounds like it’s coming from the passenger side. Kind of sounds like somebody clicking a mouse repeatedly, not sure what that noise would point to. Do you have any ideas?

 

[rdezs]

The clicking or ticking sound is usually a lifter that sticking. Usually a bad check ball in the lifter.... Or it's full of crud keeping the check ball open. What happens is the lifter can't pump all the way up and that puts slack in your valve train. The sound you hear is the end of the lifter bouncing off the camshaft lobe or the push rod. Likely both at each end of the lifter. You may also hear the top of the push rod I mean against rocker, The rocker tapping against the valve stem. Considering on a 20 minute drive those little ticking sounds are hammering away thousands of times.... Not something you really want to ignore. It's best to replace all lifters at the same time and inspect for any bent push rods and whatnot. Great time to have the cylinder head gone over by your favorite machine as you will have both cylinder heads off.