Rod Knock? Lifter Tick? Flex-plate noise?

[johnalbe]

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 boots. 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 !

BTW...The tick usually goes away after the manifold heats up and expands.
Just search on YouTube for many videos on this issue.

 

[Elite]

hi all, i'm getting a valve tick on my '12 tahoe. should i be running 100% synthetic or what's a potential remedy? thanks.

 

[wjburken]

hi all, i'm getting a valve tick on my '12 tahoe. should i be running 100% synthetic or what's a potential remedy? thanks.

You might get better a better response if you started a new thread in the 2007-2014 section and not on a thread in the 2000-2006 section that was last posted on 4 months ago.

That being said, if you are already getting lifter tick, going to full synthetic could cause you more harm than good by breaking up sludge and causing it to plug things up.

 

[JonnyTahoe]

That sucks the idiot's who owned it before you never changed the oil at the proper intervals. I had absolutely no sludge in my pan when I did the pump tube o-ring. you did a timing chain good for you. I too noticed the slack when I had my pan off but figured with almost 300k on it I'll see how much longer it will go. I was amazed at how small the chain was, just a tiny single roller.

 

[JonnyTahoe]

View attachment 236160 View attachment 236160

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.

Flex Fuel like E-30,E-85 at most stations in the upper Midwest. Some blends can be as much as 100 octane.

 

[Summajet]

If you remove the intake and the valley cover, using a flash light you will be able to see some of the cam towards front and rear. I just rebuilt mine. I have a 03 flex fuel 5.3l. The #2 cyliner lifter bearing failed and created a flat spot on the lifter and a flat spot on the cam lobe. Your is definitely a lifter but it also sounds like the pressed in bearing for the connecting rod is bad.
I hope yours is not too bad. I thought mine was going to be easy, remove the heads, replace the lifters until i saw the cam lobe all galled up. One thing led to another and then i ended up tearing to motor completely and rebuilding it. One note, if you replace the crank sensor with an Ac delco make sure you use the correct sensor harness. I was getting no spark on mine for two weeks. Today went to advance and got a Bwd and it fired right up.

 

[Rocket Man]

@biigSam did you ever figure out what the knock sound was?