Rod Knock? Lifter Tick? Flex-plate noise?

[biigSam]

Sounds like a weak lifter.
Worst case would be a worn lobe on the cam.

That doesn't sound too bad. I find these GMs LS engines are fairly easy to service.

 

[Tonyrodz]

Funny you commented, I was just going through your build thread lol. But it's the flex fuel sensor. This thing lit up like a Christmas tree when I plugged the ABS module back in.. old owner unplugged it... smh

From what I understand those are pricey. Thank god I don't have flex fuel.

 

[Fless]

@Tonyrodz, you're missing out on the benefits of ethanol!

 

[Tonyrodz]

@Tonyrodz, you're missing out on the benefits of ethanol!

Eh. I don't think they even sell that at regular stations around here. I've never seen it for sale, but again I've never needed it either.

 

[PG01]

Im no mechanic but thats too deep(pitch?) of a sound for lifters to me, sounds more like piston slap ... which the early ls’s were known for.

 

[PG01]

Im no mechanic but thats too deep(pitch?) of a sound for lifters to me, sounds more like piston slap ... which the early ls’s were known for.

Edit ... more of a tap from piston on block than a tick from up top.. if that makes sense

 

[Michigan]

A bad push rod you shouldn't have to pull the heads. Lifters yes.
Then there is always the wrist pin knock.
Kind of rare but based on the lack of maintenance you describe? Not unusual.

A buddy of mine says he thinks my truck has a wrist pin knock. You replied to my thread about “I’m being told my engine is bad”

 

[swathdiver]

Eh. I don't think they even sell that at regular stations around here. I've never seen it for sale, but again I've never needed it either.

Looks like Jersey is E85 free, the whole state!

A buddy of mine says he thinks my truck has a wrist pin knock. You replied to my thread about “I’m being told my engine is bad”

There's a new member who just posted pics of one of his wrist pins that fell out of the hole in his oil pan.

 

[Summajet]

Hey, did you start replacing the lifters on your vehicle yet? I have to do my lifters as well...

 

[johnalbe]

1st post and somewhat new owner of a 2002 GMC Yukon 2WD 130k fairly low confirmed with carfax. So it's legit.

Did an oil change and basic tune-up(plugs and wires) when I first got it and after a 600-mile road trip from dropping my nephew off at college, the engine started to tick/knock. My first thought was "****! It's knocking already"

Initially, I thought it was the rod bearing knock. Changed that.. no cigars
- Then I replaced the flexplate because, after some research, folks were having that issue as well.. no cigars
- Replaced the oil pump and timing set because after diagnosing there was too much slack.. no cigars
- CEL came on for knock sensors, 1 was flooded with water. Changed both with new wires and we're still in the same state.

In its current state, I've put about 5-6k miles on it.. with the tick lol. There's no loss in power. With the music on, I can barely hear it from the cabin. Definitely audible to everyone.

The oil(only 5w30 mobil1) looks normal between the 3 oil changes I have done. Now.. when I pulled the pan off to service the rod bearings and oil pump, there was a SHIT TON of sludge. I'm talking about prebaked brownie sludge! smfh I cleaned it out and it looks new again. This just tells me the previous owner did shit for maintenance.

After closer diagnosing with a long 3 ft screwdriver, the tick is the loudest from the #1 cylinder. I plan on pulling the valve cover and checking the rockers. I hope it's not a collapsed lifter or a mushroomed/shortened push rod. I really don't want to pull the heads off. Hoping it's something that just needs an adjustment.

I'll record a video of a cold start for you guys, when I get on my break.. lol I'm at work typing this out at the moment.

These are the lifters I'm looking at purchasing if it is.. or should I go with LS7 OEM lifters as I've read in other posts?
View attachment 224055

It's probably a broken exhaust manifold bolt. It will sound like a bad lifter....or an engine knock ...trust me.
It's a real common problem and they make patch-up brackets for $30 if you don't want to fix it the long way. New manifolds are only $60 with gaskets and new bolts. The heads of the bolts bust off all the time. GM should have recalled the vehicles but never did. I just ordered the repair bracket for my 6.2L Escalade 2007. VERY COMMOM ISSUE ! THAT'S YOUR TICK !