Sudden Loud knocking

[Featherburner]

Originally Posted by 1984camaroz28

Pull the valve covers...

This!

[Lt1_8U]

Originally Posted by Featherburner

This!

x2 !

[S.J.SLEEPER]

Originally Posted by alamantia

I hear the loud knock we are talking about like 3 times in that clip, but I hear a lesser tap more in sequence with the RPM of the motore in the backround. Maybe this is stupid thinking here but is it possible that a broken exhaust pushrod or rocker is allowing the cylinder to fire and that loud bang is a backfire thru the intake? Is that possible or am I stupid? Its not hard to yank valve covers...

I listened to the vid. I have heard that exact noise come from a broken rocker. sounds like combustion popping back through the intake.
Jake pull valve covers. and if you find broken rocker or pushrod, pull intake too cause I guarrantee the intake port is melted to shiiieet from the combustion coming back through the intake. I know this cuz a scorpion rocker broke on me and did this exact thing!!!

[qwikz28]

Originally Posted by S.J.SLEEPER

I listened to the vid. I have heard that exact noise come from a broken rocker. sounds like combustion popping back through the intake.
Jake pull valve covers. and if you find broken rocker or pushrod, pull intake too cause I guarrantee the intake port is melted to shiiieet from the combustion coming back through the intake. I know this cuz a scorpion rocker broke on me and did this exact thing!!!

Thanks fellas. I was planning on pulling the valve covers tomorrow morning. This question may seem silly, but how can I check for a bent/broken pushrod? Will it be obvious? My plan at this point is pop the covers and if I see nothing amiss, to have someone turn the crank to see if all the rockers are operating as they should.

[Lt1_8U]

just have to pull them out and inspect them, roll them on a flat surface and you will see if they are bent. someone correct me if im wrong but couldnt he take the plugs out, pull the coils off and have someone crank the motor while he or someone looks at it without the covers on. then he could inspect the motor while it turns over without the engine running.

[qwikz28]

Sadly, I think pulling the valve covers is easier than getting to the plugs. I suppose that will be my next step if pulling the valve covers yields no answers.

[qwikz28]

Do I still need to pull the drivers side?

[WildBillyT]

Curt for the bullseye!

Originally Posted by qwikz28

Do I still need to pull the drivers side?

For what it's worth that's kind of good news.

[coolmanvette75]

Thank god thats all it is...

[LTb1ow]

And that is why I will leave the aluminum to beer cans.

[1984camaroz28]

Put stock rockers back on it.. that all we run on are hyd roller stuff

[qwikz28]

Originally Posted by WildBillyT

Curt for the bullseye!
For what it's worth that's kind of good news.

Originally Posted by coolmanvette75

Thank god thats all it is...

Amen to that!

Originally Posted by 1984camaroz28

Put stock rockers back on it.. that all we run on are hyd roller stuff

Don't have them. Broke those too

[sweetbmxrider]

How bout the intake

[V]

i have a full set of stock rockers with stands, they are urs free if u want

[BonzoHansen]

Originally Posted by qwikz28

Do I still need to pull the drivers side?

yes for when you replace them too.

WTF, what brand were those?

[alamantia]

Damn, man, i was hoping it was something simple like a starter, but it appears my second guess was right, rockers are no big deal either though. I run a TR230 cam with PAC 1518 springs and hardened pushrods and I left the stock rockers in mine.

[qwikz28]

Originally Posted by V

i have a full set of stock rockers with stands, they are urs free if u want

Yes please. Can I pay you for them in cash or beer at least?

Originally Posted by BonzoHansen

yes for when you replace them too.

WTF, what brand were those?

Those were Yella Terras. I originally put them in my car when I did my first cam, Josh swapped them out when he realized I had put them with incorrect length pushrods, and we decided that the stockers were better. When that motor blew, the rockers broke when the head blew a hole in it, TTP put the Yella Terras back in to save some money instead of having to purchase new rockers. They said it would be better with the large cam they were throwing in the motor as well. I just did some searching on Tech and it seems that these rockers have a tendency to break and although once popular, people are now avoiding them like the plague.

I was jumping for joy when I found the broken rocker. I was dreading having to replace the short block. Thank you all very much for helping me with guidance throughout all this; especially Anthony (Alamantia) who loaned tools, came out to check out the car for me, has been in constant correspondence via calls and texts to tell me what to do, and for most of all, for encouraging me to continue looking for the problem and not giving up.

Gosh, that sounded like an award acceptance speech.

[qwikz28]

Originally Posted by alamantia

Damn, man, i was hoping it was something simple like a starter, but it appears my second guess was right, rockers are no big deal either though. I run a TR230 cam with PAC 1518 springs and hardened pushrods and I left the stock rockers in mine.

I'd call it a victory. Everyone was saying it was a spun bearing. Thanks again man. I owe you a beer at the very least. See the above post.

[sweetbmxrider]

Once you posted that video, it was pretty clear that you were blowing compression out. Glad you found the issue and that its not the end of the world......or motor.

[S.J.SLEEPER]

DO NOT get all excited yet Jake.
1) I can almost guarantee that you will need to replace intake or atleast epoxy & grind it due to the backfiring through the intake
2) you will need to pull the head off,....sorry to tell you this, but very common for when rocker breaks, the pushrod beats around on top of lifter and pops out the retaining clip, which then releases thelifter body & spring from its case.
3) OR... you can use your 20/20 vision and a flashlight to look down in hole to confirm clip is completely seated, but MAKE SURE 110% that it is.
Cuz if you don't, the lifter will evebtually come dissasembled down the road and circulate into the rest of your engine. And then you will no longer be getting off easy.

p.s. make sure you find the rest of the rocker (hardened seat part)

[S.J.SLEEPER]

Originally Posted by WildBillyT

Curt for the bullseye!

Thanks, As soon as I heard the noise in video I knew exactly what it was!!!

I'm not to familiar with lulz,negg,first beer or any other of that jrz sho ebonics....but I do know Ls's... and unfortunetly the other boat anchors that GM produced.

[BonzoHansen]

Originally Posted by S.J.SLEEPER

DO NOT get all excited yet Jake.
1) I can almost guarantee that you will need to replace intake or atleast epoxy & grind it due to the backfiring through the intake
2) you will need to pull the head off,....sorry to tell you this, but very common for when rocker breaks, the pushrod beats around on top of lifter and pops out the retaining clip, which then releases thelifter body & spring from its case.
3) OR... you can use your 20/20 vision and a flashlight to look down in hole to confirm clip is completely seated, but MAKE SURE 110% that it is.
Cuz if you don't, the lifter will evebtually come dissasembled down the road and circulate into the rest of your engine. And then you will no longer be getting off easy.

p.s. make sure you find the rest of the rocker (hardened seat part)

can he use a bore scope to look?

i'd still rather do lifters then a whole bottom end!

[coolmanvette75]

Originally Posted by S.J.SLEEPER

Thanks, As soon as I heard the noise in video I knew exactly what it was!!!

I'm not to familiar with lulz,negg,first beer or any other of that jrz sho ebonics....but I do know Ls's... and unfortunetly the other boat anchors that GM produced.

Hey thats me

Qwikz, what intake are you running? Now might be a good time to upgrade if your current one id damaged...

[LTb1ow]

More importantly, if this is not the first time this has happened, you should figure out what in your valvetrain is causing your rocker to be the weak link.

Too much spring pressure, or to much pushrod travel etc etc

[Jersey Mike]

Jake,
Glad you two were able to wrench on it today and figure it out. If you end up needing to replace the intake, I have my stock manifold tucked away in storage that you can have.