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tapping/slapping noise

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Old Apr 12, 2008 | 10:39 PM
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Default tapping/slapping noise
I have a tapping/slapping noise from the front of my 5.7L 350 in my 79. I have ruled out a valve tap for now. Can my timing chain be hitting its cover? If so can it be adjusted? Do the chains stretch over time a get loose? the noise apprears after 1500 RPM.
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Old Apr 12, 2008 | 11:47 PM
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The OEM sprocket on the cam had nylon teeth which can come off in chunks. If it does you will hear a ticking or clacking coming from that area. You can localize the noise by using a piece of hose or a long screwdriver and with one end near your ear, put the other on the timing cover. Be very careful around the fan!!!!!!

If that is the problem, a new timing set is in order. Best bet is a double row true roller.

Cheers,
Pete
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Old Apr 13, 2008 | 01:33 AM
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Fig A for me would be the fuel pump believe it or not if you've not done anything recently to your engine.
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Old Apr 13, 2008 | 08:22 AM
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Check for exhaust leak before ripping the thing apart, will sound just like what you describe
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Old Apr 13, 2008 | 10:48 AM
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thank you forum, now I have at least three trouble shooting tasks I can try. That's the fun of it, right...
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Old Apr 13, 2008 | 10:55 AM
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A worn fuel pump pushrod can make a tap like valve tap. Said to be "impossible" to find.
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Old Apr 17, 2008 | 11:35 PM
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Default problem solved by fuel pump
just want you to know I replaced the fuel pump and the noise went away. glad I did not tare into the timing chain and gear. Thanks forum.
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Old Apr 18, 2008 | 03:55 PM
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Originally Posted by cruise83
glad I did not tare into the timing chain and gear. Thanks forum.
Me too! Always check the easiest first. I had the cam sprocket failure, but not the fuel pump push rod problem.

Cheers,
Pete
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Old Apr 18, 2008 | 11:47 PM
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Default one last issue a crimped furl line
see the picture, does anyone have pics about how to connect the fuel line to the pump?? Mine is crimping...
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Old Apr 18, 2008 | 11:51 PM
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by the way, I needed to turn the ignition a couple of times to turn the cam shaft so the fuel pump rod could depress far enough to allow the fuel pump arm to insert into the proper position. Several of the books and manuals I had did not discuss this step. Using vaseline to hold the rod in place did help,
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Old Apr 19, 2008 | 06:57 AM
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Originally Posted by cruise83
see the picture, does anyone have pics about how to connect the fuel line to the pump?? Mine is crimping...

anyone have a picture or solution keep the fuel line from crimping?
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Old Apr 19, 2008 | 07:18 AM
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Several.
Formed hose, routing & length, fitting to pump at correct angle & also a hose clamp can be used to hold hose open.
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