1995 Nissan Truck noise in the motor

1995 NISSAN TRUCK
200,000 MILES • 4 CYL • 2WD • MANUAL
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MICHAEL BETHKE
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the motor has a loud rattling noise from the topend of the motor.there is some oil and I was told by a friend that the oil pump may be bad but there oil on top of the head.it sounds like its coming from the back of the head
Aug 7, 2010 at 8:02 PM
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KHLOW2008
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Hi michael bethke,

If it is the oil pump failing, the oil pressure indicator would light up. To confirm if that is the cause, get the oil pressure checked.

Remove the valve cover tyo inspect the rocker arms and cam carriers. If there is a lot of sludge caking ( usually due to use of oil treatments ) on the components, most likely the oil passage is clogged somewhere. This woud cause wear on the rockers and the insufficient oil passing through would result in the rattling.
Aug 8, 2010 at 1:46 AM
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MICHAEL BETHKE
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tuke the valve cover off and turned they motor over and it is getting alot of oil to the top of the motor.sounds like when it is running that it maybe coming from one of the rocker arms
Aug 8, 2010 at 12:15 PM
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KHLOW2008
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Check the rocker arms for excessive movements in its seats.

If the problem occurs only when temperature is hot, check the hydraulic lash adjusters (HLA) ( valve lifters). If they aer bad, the engine would rattle. Take note that insufficine engine oil can result in the HLA being noisy.
Aug 8, 2010 at 12:35 PM
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MICHAEL BETHKE
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when you start it up it starts making the noise right off
Aug 8, 2010 at 12:57 PM
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KHLOW2008
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That could mean the HLA are bad and requires replacement.

Turn the engine so that the camlobes are away from the rockers. Test the HLA by pulling and pushing on the rocker arms to test for excessive clearance between the camshaft. Any rocker arm that has excessive clearance is bad and requires replacement.
Aug 8, 2010 at 1:19 PM
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MICHAEL BETHKE
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what is hla and the rockers have alot of clearance more on some then others
Aug 9, 2010 at 8:13 AM
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KHLOW2008
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HLA = hydraulic lash adjuster, meaning the valve lifters.

Those that have a lot of clearance indicates the HLA is not extended as much as required, indicating they are faulty.
Aug 9, 2010 at 9:06 AM