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-   -   Sudden Loud knocking (http://www.njfboa.org/forums/showthread.php?t=58368)

Featherburner 01-05-2012 08:47 PM

Quote:

Originally Posted by 1984camaroz28 (Post 800528)
Pull the valve covers...

This!

Lt1_8U 01-05-2012 08:52 PM

Quote:

Originally Posted by Featherburner (Post 800544)
This!

x2 !

S.J.SLEEPER 01-05-2012 10:04 PM

Quote:

Originally Posted by alamantia (Post 800337)
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 01-05-2012 10:47 PM

Quote:

Originally Posted by S.J.SLEEPER (Post 800599)
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 01-06-2012 05:33 AM

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 01-06-2012 08:23 AM

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 01-06-2012 11:31 AM

https://lh6.googleusercontent.com/--...106_122830.jpg
Do I still need to pull the drivers side? :)

WildBillyT 01-06-2012 11:32 AM

Curt for the bullseye!

Quote:

Originally Posted by qwikz28 (Post 800792)
https://lh6.googleusercontent.com/--...106_122830.jpg
Do I still need to pull the drivers side? :)

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

coolmanvette75 01-06-2012 11:32 AM

Thank god thats all it is...

LTb1ow 01-06-2012 11:33 AM

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

1984camaroz28 01-06-2012 11:36 AM

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

qwikz28 01-06-2012 11:43 AM

Quote:

Originally Posted by WildBillyT (Post 800793)
Curt for the bullseye!
For what it's worth that's kind of good news.

Quote:

Originally Posted by coolmanvette75 (Post 800794)
Thank god thats all it is...

Amen to that!

Quote:

Originally Posted by 1984camaroz28 (Post 800797)
Put stock rockers back on it.. that all we run on are hyd roller stuff

Don't have them. Broke those too

sweetbmxrider 01-06-2012 12:09 PM

How bout the intake :-?

V 01-06-2012 12:23 PM

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

BonzoHansen 01-06-2012 12:32 PM

Quote:

Originally Posted by qwikz28 (Post 800792)
Do I still need to pull the drivers side? :)

yes for when you replace them too. :rofl:

WTF, what brand were those?

alamantia 01-06-2012 12:48 PM

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 01-06-2012 12:53 PM

Quote:

Originally Posted by V (Post 800828)
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?
Quote:

Originally Posted by BonzoHansen (Post 800835)
yes for when you replace them too. :rofl:

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 01-06-2012 12:54 PM

Quote:

Originally Posted by alamantia (Post 800855)
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 01-06-2012 01:08 PM

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 01-06-2012 01:17 PM

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 01-06-2012 01:24 PM

Quote:

Originally Posted by WildBillyT (Post 800793)
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 01-06-2012 01:42 PM

Quote:

Originally Posted by S.J.SLEEPER (Post 800870)
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 01-06-2012 01:55 PM

Quote:

Originally Posted by S.J.SLEEPER (Post 800874)
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 :lol:

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

LTb1ow 01-06-2012 02:01 PM

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 01-06-2012 03:03 PM

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.


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