1995 Nissan Truck noise in the motor

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.

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.

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.

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.