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#66585 09/28/2006 6:07 PM | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | Bobs54,
Valve train noise isn't usually a deeper knock to the ear...it's usually a clicky/clacky/tappy!
Wrist pins usually make a lighter noise at idle. What you are describing sounds like a connecting rod bearing to me.
If this is true, you should be able to make it knock at will. With the truck parked and hood open, you should be able to bring the RPM's up to say 1000, pop the throttle a little and let it go. If it is a rod, when it "relaxes" you should hear a rattle, or knock.
Sometimes you can pull plug wires and isolate the problem to a cylinder.
Keep in mind that everything from a water pump to a cam gear can make a knock which can be transmitted through the big iron block like a drum.
A bad rod bearing would certainly act up as the oil thinned and pressure was reduced.
Do some detective work with a rubber hose held to your ear as you run the engine. Good luck.
Stuart | | |
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