Volvo penta 5.0 knocking sound

Lou C

Lou C

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Try disconnecting the belt for a few sec to see if it stops, if so spin each accessory and see if any feels rough or is noisy. Replace as needed. It sounds more like an engine sound to me like a bad lifter or bent push rod/stuck valve. Your best bet is to get a mechanics stethoscope because that will really help narrow it down. Could be a stuck valve (corrosion) causing a bent pushrod or bad lifter. Could also be an exhaust leak from the manifold to cyl head gasket.
 
J

John1214

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Sep 5, 2021
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Lou C said:
Try disconnecting the belt for a few sec to see if it stops, if so spin each accessory and see if any feels rough or is noisy. Replace as needed. It sounds more like an engine sound to me like a bad lifter or bent push rod/stuck valve. Your best bet is to get a mechanics stethoscope because that will really help narrow it down. Could be a stuck valve (corrosion) causing a bent pushrod or bad lifter. Could also be an exhaust leak from the manifold to cyl head gasket.
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Thanks I will remove the belt and see what I find.
 
Lou C

Lou C

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Just watch the engine temp don’t let it overheat
 
bruceb58

bruceb58

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May also want to pull the drive and run it for a few seconds to make sure its not from the coupler or drive area.
 
bruceb58

bruceb58

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John1214 said:
Would a loose/defective coupler be that loud and Consistent?
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Possibly. When was the last time you pulled the drive?

Even if it wasn't it and it is the engine, the drive needs to come off anyway to pull the engine
 
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Bretbyron

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Sep 6, 2021
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That sounds is horrible but sounds external to me. Was that in gear at idle? Sounds like a U-joint or something in the input shaft.
 
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