Knock Knock

icanfixall

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Actually needle bearing roller lifters are the better of the choices. Seems in the early engines we had issues with roller freezing up and flattening the cam. There has been some posts about this bushing veres the needle bearing. Clearly the needle bearing won out. I do understand the coverage of a bushing compared to needle bearings but I'm using needle bearings and no issues. Many others have needle bearing roller lifters and if there was an issue we sure would see it here before any place else. This forum puts many hundreds of thousands of miles on the idi engine every year. If you want a new set of bushing bearing roller lifters I have a new set that I will sell for $100.00. PM me if interested.
I went to ebay and found many sets of roller lifters for our engines. Heres an example. Try searching under Hummer lifters or gm diesel lifters or 7.3 roller lifters. Our lifters fir the early 5.7, 6.2, 6.5 and the hummer diesels.
http://www.ebay.com/itm/2008-2009-H...Parts_Accessories&hash=item3f2a3f9b32&vxp=mtr
 
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HammerDown

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Could the rapping be 'fuel knock'?
Are you sure you're hearing 'chuffing' at the intake, and you post a video of it?
 

icanfixall

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Have you talked to Mel about the leak since the new pump was installed and how long ago was the pump installed. A leak like you mentioned is not normal and will drain fuel causing hard starts with long cranking. Fix the leak. I did hear the sound you wanted to post. Might be a lifter but from this side of the screen its really tuff to say what it is. It almost sounds like the air filter rattling when its cranking over.
 

Diamondwhips

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Have you talked to Mel about the leak since the new pump was installed and how long ago was the pump installed. A leak like you mentioned is not normal and will drain fuel causing hard starts with long cranking. Fix the leak. I did hear the sound you wanted to post. Might be a lifter but from this side of the screen its really tuff to say what it is. It almost sounds like the air filter rattling when its cranking over.

I planned on calling Mel today. For what its worth it'll make the same noise with the air filter off. It doesn't sound right but not sure there's anything wrong in the engine. That's why I'm asking you guys.
 
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riotwarrior

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I can clearly hear the kathunk...but I'm not sure it's a chuff...do the same video, close up to intake opening with no air filter assembly on it, since you say you can still here it.

A valve chuff is a very distinct sound, and intake/exhaust while running it still a distinct sound, not a knock unless...a valve got bent that could be a clatter.

Does the knock/clatter go away or does it remain?

If it goes away when warmed up and no chuff, this is not likely a valve bent as it would stay.

Have you removed VC's to watch rockers in action? Might be an idea...

Sorry for all the ?'s but without answers makes it for pretty much broad spectrum analysis.

Well keep show n tell, we'll see what we can do to assist.

please go direct to the moose master himself, I"m sure that's the best route to deal with the leak as I have nothing to offer other than that.
 

Diamondwhips

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I can clearly hear the kathunk...but I'm not sure it's a chuff...do the same video, close up to intake opening with no air filter assembly on it, since you say you can still here it.

A valve chuff is a very distinct sound, and intake/exhaust while running it still a distinct sound, not a knock unless...a valve got bent that could be a clatter.

Does the knock/clatter go away or does it remain?

If it goes away when warmed up and no chuff, this is not likely a valve bent as it would stay.

Have you removed VC's to watch rockers in action? Might be an idea...

Sorry for all the ?'s but without answers makes it for pretty much broad spectrum analysis.

Well keep show n tell, we'll see what we can do to assist.

please go direct to the moose master himself, I"m sure that's the best route to deal with the leak as I have nothing to offer other than that.


Yes the clatter goes away. The noise isn't there when its warmed up. I have removed the VCs to take a look I don't see or hear anything out of the ordinary.

Could the noise be a bad cdr valve?
 

Diamondwhips

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So a little update and some questions.

I decided to pull the intake and inspect the lifters and cam (what I could see of the cam while still in the block). I didn't find anything out of the ordinary.
I did talk with my machinist some more and asked him some more detailed questions about the guides he used and how he surface the heads and whether or not he check the valves afterwords. He didn't miss a thing from what I gather. So right now I think the head work was done correctly any suggestions on the next step?
Some other things I hoped you guys could help me with.
Does air in the fuel system cause a knock sound?
I have 3 push rods that have the copper end isn't on the same end as the witness mark (witness mark being a dote about an 1 inch down) on the shaft of the push rod. Is this a problem and which end goes up?
Does anyone have the torque spec for the keeper on the lifters?

Thanks
 
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