Lazy Lifter?

[Mike534x]

Well this is a new one, so yesterday was the first time I have heard anything abnormal coming from the engine bay and I'm trying to see if anyone has any guesses as to what it could be. I was out and about, upon starting up the Envoy (after it was already warmed up) I was greeted with this ticking/tapping noise. Initially I figured maybe it was related to the fan clutch, as I believe its the original OEM one. But this sounded more like a tapping/ticking, coming from what I think sounds like the right side of the engine. It "almost" sounded like the noise I had in my old Envoy with the I6, when one of the spark plugs had worked its way lose and was arching inside the cylinder. The noise originally lasted roughly 3 minutes give or take after start up, this was after it was fully warmed up and sitting for an hour or so. I recorded a quick video of the noise, excuse my bad camera skills, this is from sitting over night. Wasn't exactly expecting it to do it again, figured it was a fluke but you can hear it slowly fade away, well that is until you give it a little gas and its still there but eventually clears up.

Oil is full, no loss of oil pressure, no shaking/abnormality when driving or sitting at idle. Is this the typical valve noise that everyone speaks so much of? It definitely doesn't sound like its knocking, but I'm also wondering if I've developed a lazy lifter. I've still got roughly 2k more to go until my next oil change which I was thinking of adding Marvel Mystery Oil in to see if it helps. Maybe I should try switching to a heavier grade of oil? Its been in the mid to high 80's for a few days now so I'm not sure if the temperature is the cause of this.

 

[Mooseman]

In the video, you talking about that noise only right after startup? Maybe a cracked exhaust manifold? The warmup would support that theory and apparently one of them has a tendency of cracking.

 

[Mike534x]

That's right! Its the initial loud tapping you hear in the beginning. Here's another video of it from the passenger side.

 

[Capote]

It kinda does sounds like an exhaust leak, especially if it happens to quiet down after it warms up.

 

[Mike534x]

Yeah it does quiet down, but doesn't fully go away. The little tubing that acts as the drain for the condensation after the A/C is running had popped off a few weeks ago in the drive way, I have no idea how it goes back on but I assume it acts as a directed drain for the condensation in the heater core/A/C so I'm guessing the water dripped onto the manifold and this is probably what has happened.

This doesn't look like it'll be a walk in the park if I need to tear that sucker out to replace it.

 

[Capote]

Yeah it does quiet down, but doesn't fully go away. The little tubing that acts as the drain for the condensation after the A/C is running had popped off a few weeks ago in the drive way, I have no idea how it goes back on but I assume it acts as a directed drain for the condensation in the heater core/A/C so I'm guessing the water dripped onto the manifold and this is probably what has happened.

This doesn't look like it'll be a walk in the park if I need to tear that sucker out to replace it.

That's very possible, and the OEM manifold eventually crack anyway it would seem. When mine did I upgraded to the '08/'09 one, which was a better design and the exhaust flows better as well. It is already really rusty under the 4 layers of heat-wrap I carefully wrapped all over it. If it breaks again i'm just getting Kooks or OBX headers so I don't have to worry about that again or deal with breaking heads off bolts....

 

[Mike534x]

I forgot they were prone to cracking, what are the odds of the manifold bolts breaking for no reason? I found this bolt wedged between the lower half of the heat shield where the manifold is connected to the cat/flange. I was able to see it through the wheel well, and I think I found the spot where it came from. There's this hole above the spark plug #6 that looks like the bolt may have come from there. I do recall hearing a "pop" or clunk metallic sound coming from the truck when I was walking away before I noticed the ticking noise. I didn't think anything of it but now it would make sense.

I included a picture of the bolt and spot I think the bolt came from. Now if its just a bolt thats easy, but getting the other half free of the head looks like it will be a different story.

The first bolt looks like its been sitting somewhere for awhile, it definitely wasn't in the spot where I found it during the times I have been underneath or in the wheel well. Whatever happened to the bolt in the second picture is a mystery, it looks like half of it is still in the block, but I cannot find it so I'm assuming it must have fallen off somewhere on the way home.

Update: after driving to work this morning, the sound was still present until the truck started getting to operating temp and then it started to quiet down. You can still hear it somewhat under acceleration but it's not as noticeable. So my leak is either from that missing bolt or there is a crack somewhere in the manifold.

 

[Mooseman]

Definitely those be manifold bolts. They do have a reputation of popping off like that. So much so that Dorman has come up with a bracket to cinch down the manifold at the ends of the head using unused bolt holes. Easier than pulling the manifold and removing the broken bolts.

 

[Mike534x]

You're right, took it over to a shop and 3 manifold bolts need to be extracted. The manifold is intact which is a plus, but they want $650 just to do the extraction, this is more then another shop quoted to do a new manifold. Now I need to do some searching, I would attempt this myself but I'm afraid of botching the extraction.

 

[Mooseman]

Did you check for that Dorman bracket? Fixing two of the three might do it.

 

[Mike534x]

I was looking but they don't seem to have it listed for the Envoy/Trailblazer with the 5.3.

Edit: Never mind, I found it. I had to search under a Yukon for it to list the part number. It comes up with 917-142, it looks like it should work. The shop said 2 on #6 broke and 1 on #8 is broken as well. I don't think it should cause harm having the clamp on #6. There was a guy we found locally that offered to do the job for $150 being a shade tree/travel to home mechanic, with almost a decade of experience. Didn't seem to bad, still debating if its worth it.

 

[Mooseman]

I don't know if it will work. I think it works if it's just the first or last ports in the head. Don't know if it will work for a middle port.

 

[Mike534x]

They have two style brackets, one that sits over the middle ports (part number I listed), and the one that attaches behind the engine block to clamp down on the last port. Not entirely sure if I can even reach my hand back there to even get the bolts started or wrenched down due to how close the block is to the firewall already.

 

[Mooseman]

Ah, good to know that both are covered. Space seems to always be an issue on these trucks no matter the engine.

 

[Mike534x]

Are these repair kits good as a long term solution, or do they fit the "it'll hold for now" type of fix? I'm looking to order it and install it this weekend, I may end up trying the bracket to clamp down #6. I think if that's clamped down, it should hold up and eliminate the ticking. If this were on my Avalanche, I can see myself doing the rear clamp with ease but it amazes me GM still found a way to shove as much stuff they did into this small cramped engine bay.