bad knock please help. VIDEO

smokin247

smokin247

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Aug 29, 2010
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a year and a half ago on my way home from work my engine developed a knock. Its been off the road ever since. I was building it up with new everything and planned to get into the bottom end to check everything but I backed off the build and im just running a 63 single. I've got in back together and test drove it. Drives fine except for the knock...

The knock is always the same tone but speeds up with RPM and can be head clearly over my 5" straight exhaust.. I've tried pumping the lift pump primer and no change in sound. The noise seems to be coming from the front of the engine. Using 3/4" tubing ive listened every area of the engine. Its loudest listening through the #1 valve cover.
The only thing i can think of is a connecting rod or broken tappet/ bend push rod. But when i checked the valves all of them were in spec. Wouldnt a tappet or pushrod problem throw the valve out of spec?

I'm hoping its in the valvetrain because I have a Hamilton cam, tappets, pushrods, and valve springs to put in but i need to run a new fuel system once they are installed and dont have the money right now.

Please give me ANY ideas!!!!!!! I need to figure this out!!

Knocking sound cummins 12v - YouTube
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.I cant get the video to display but heres the link^^^^^^^^
 
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I definetely think its the valvetrain. It would be louder if it was something worse. That's my thinking anyway
 
I hope your right!! I havent been able to find anyone with any experience to listen in person.
 
My vote is in valve train also I'd pull pushrods and check to make sure they are perfectly straight.
 
yeah that doesn't sound like a deep enough tone to be a lower end knock. its hard to tell really on video but that's my opinion also, start with the easy stuff first at least, check push rods like mentioned and lash. you could also cut the filter open and see if theres any material in it, if there is that would help tell you what it is depending on what the material is.
 
I too agree with valve train. Too light of a sound and too fast to been a lower end knock. I am going to guess on looses valve clearances......hope its that simple.
 
I checked valve lash already and all of them were perfect. which is what confused me because i expected them to be off if there is something wrong with a tappet or push rod. But I will be checking pushrods and most likely just installing the new cam and running a new fuel system. I just hope I find the problem and its fixed with the new valve train.
 
small update:
When replacing the cam found that my cam gear, injection pump gear, and vacuum pump gear all have teeth chipped and missing. I'm not sure what caused it but i believe thats my noise (KDP is tabbed)
 
smokin247 said:
small update:
When replacing the cam found that my cam gear, injection pump gear, and vacuum pump gear all have teeth chipped and missing. I'm not sure what caused it but i believe thats my noise (KDP is tabbed)
Click to expand...

I'm diggin your new avatar. :Cheer:
 
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