Well, if it goes away after it kicks down and idles, most likely it's exhaust manifold/sAlways worth checking/double check manifolds, they all get to a point of air leak somewhere
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Well, if it goes away after it kicks down and idles, most likely it's exhaust manifold/sAlways worth checking/double check manifolds, they all get to a point of air leak somewhere
I'm in way over my head hear with y'alls knowledge base, I'm just trying out site as a newbie, peace!Well, if it goes away after it kicks down and idles, most likely it's exhaust manifold/s
I assume you’re talking exhaust manifolds? Due to broken bolts that are so prevalent? Please explain, that’s kind of a blanket statement. And I have to disagree on the part about all of them regardless. Broken exhaust manifold bolts is a known issue with these engines but there’s plenty of them running around with broken bolts that don’t leak.Always worth checking/double check manifolds, they all get to a point of air leak somewhere
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
I hope so too! I planned to get back to it this afternoon, but we had a ton of rain come through which ruined my plans.Looks like you figured it out, a stuck lifter.
Being on #1 that should be really easy to try the hammer method to unstick it if not too bad.
With that amount of sludge, i would tread very carefully with any sort of crank case cleaning agent like seafoam.
I might try seafoam down the intake/smoke out the neighbors method in hopes of cleaning up carbon that might have gummed rings.
But once you have it fixed up, do some oil changes at 3k miles using a quality full synthetic to slowly remove the gunk.
I hope you get it unstuck w/o having to pull the heads!
See, now I'm jealous of your valvetrain.I've seen worse, but that's still nothing to ignore. Even at 183K, it doesn't mean it WILL look like that. If there's hard carbon and varnish on the valve covers and insides of the heads, then it's in your entire oil system. A tiny piece of that carbon could be stuck in that #1 lifter, keeping it from pumping up. I'm not a fan of using harsh chemicals to quickly break up carbon deposits. This is exactly how chunks do damage. Tons of smoke out the exhaust doesn't necessarily mean it's breaking up and burning carbon. Most of that is just the Seafoam burning. Using detergents in high quality oil to dissolve the deposits to a liquid state, or at least very small/fine particles to carry them to the filter and out through an oil drain is safest.
This is mine at around 190,000ish miles: https://www.tahoeyukonforum.com/threads/growing-up-doesnt-have-to-suck.93510/post-1330358
See, now I'm jealous of your valvetrain.
Just gotta let the detergents in GOOD oils do their thang. They do work and are certainly worth the extra cost.
I think you should try to unstick that lifter. If it works, disable AFM then stick to using quality synthetic oil and a good filter. Change the oil when it gets dark, whether it be 2,000 miles or 5,000. It getting dark means it's dissolving the crud in the engine, suspending it and carrying it out when drained, just as it's supposed to do. As the insides are cleaned, it'll take longer and longer for the oil to get dark. Eventually, you'll reach a point where you can stick to a regular schedule that's convenient for you. I change mine every 5K. It's excessive, especially with how the oil looks after 5K, and I can go much longer. But, I rotate the tires at the same time I do oil since I already have it up off the ground and I wouldn't go more than about 6K on a rotation. 5K is a little more careful maintenance and just an easier interval to remember since multiples of 5 is easier than multiples of 6.
This is pretty much what happened to me. Never had any lifter noise and then I did a Mobil 1 oil change and it broke some gunk loose. That randomly lifter thing was accompanied by the oil pressure sensor screen getting clogged up, twice...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.
@Professor L Gee Sounds like you're on the right track. I personally don't have much faith in un-sticking a lifter because once it starts to rattle like yours.. the damage has already begun to happen to the cam and lifter.Quick update:
Had to put the Yukon on hold because (1) work was super busy for the past couple of weeks, (2) I've been car shopping to replace my Infiniti, and (3) NC has had a LOT of rain recently.
With the help of Youtube and my neighbor's fuel line release tools, I finally got the intake off. Lemme tell you, I wish I still had my swivel adapter, because those bolts in the back are an absolute pain. Other than that, it was way easier than what I would have had to do for the same job on my Infiniti (don't get me started on how the manifolds have to come off to replace a valve cover on a VQ engine... but that's for another forum).
Now to get the VLOM cover off, but I'll save that for later this week. It doesn't seem like it wants to come right off, even with the ten bolts out.
Since the tapping wasn't accompanied by any misfires or stumbles, I'm remaining optimistic that any damage is minimal. Under more generous circumstances I would go about replacing everything, but for now I'm hoping that getting the lifter unstuck will hold me for a while, along with some other preventive measures.@Professor L Gee Sounds like you're on the right track. I personally don't have much faith in un-sticking a lifter because once it starts to rattle like yours.. the damage has already begun to happen to the cam and lifter.
A rubber mallet can be useful to help break the seal of the rubber gaskets that have baked and glued mating surfaces together.
Wish I had taken a video of my own.
)It sounded much better once I cleared the codes, and it sounded almost normal when I took it for a few drives.If your happy? I'm happy, except for the vacuum leak? Whats that about?
Fix it?
I guess I need to go video my engine at idle. I swear mine is much quieter than that?
Still have a slight vacuum leak on the intake side... I think I have to tighten down the manifold. Beyond that, I've had no problems.Very nice man!
How are things with it now? What remaining problems are there?
@Professor L Gee I ran a Range but had to remove it to pass smog and the first time AFM turned back on I had A lifter collapse, the lifter ended up sorting itself out and I was able to get 6 more months out of it but ended up going with a blackbear tune to turn off AFM in the computer. HP tuners is also a good one I’ve heard, a lot more DIY than the black bear tune.Still have a slight vacuum leak on the intake side... I think I have to tighten down the manifold. Beyond that, I've had no problems.
I still have to replace the wire conduit in a few places, but that's about it. Oh, and I have a Range disabler on the way to hold me over while I decide whether to go full delete on the AFM system.
@Professor L Gee I ran a Range but had to remove it to pass smog and the first time AFM turned back on I had A lifter collapse
HP tuners is also a good one I’ve heard, a lot more DIY than the black bear tune.