1700 Nomad Noise in the motor.

[Regin]

My Nomad started making a sporadic rattling noise in the front of the motor, when the mechanic pulled it down he said that the hydraulic oil lifters on the front cylinder needed replacing, this was done and all sounded fine at first but when it was started later the noise was back.
They checked the oil pressure and it was about half of what it should be, they are still trying to find the issue. Any idea's out there? Has anyone come across this issue?

[Dieago62]

Can I ask are you running mobile1? I run amsoil but was leaving on a trip so filled with mobile and engine and tranny sounded very noisy to me so I drained it filled with rotella and it quietened down. Sure lots will argue with me but when I was a kid my chevy with high pressure oil pump ran 60psi I remember filling it with belray bike oil because it was free to me and chevy dropped to 40psi but this don't apply to you im sure. I wonder if the big end rod bearing is failing or pump itself because of the 1/2 oil pressure? a bad insert bearing will drop oil pressure big time

[Snake Ranch]

Originally Posted by Regin

My Nomad started making a sporadic rattling noise in the front of the motor, when the mechanic pulled it down he said that the hydraulic oil lifters on the front cylinder needed replacing, this was done and all sounded fine at first but when it was started later the noise was back.
They checked the oil pressure and it was about half of what it should be, they are still trying to find the issue. Any idea's out there? Has anyone come across this issue?

What kind of oil filter are you using and where is the oil pressure being tested, before or after the oil filter?

The pressure before the filter will be slightly higher than after. This referred to as the pressure differential.

I don't know your oil pump but most oil pumps have a pressure relief valve that limits the maximum pressure. If the valve is stuck or not seated properly you will have a pressure drop. A small speck of engine contaminant can hold the valve open. If it is cleaned you may not see it but the pressure may come up. Some of these things are very very small.

Some oil filters have a bypass valve and on start-up they will allow unfiltered oil into the engine especially if the engine rpm's are running high and the oil is cold creating a high pressure differential in the oil filter.

An oil pump with to much gear clearance could be another problem. Measuring gear clearance would be necessary to figure the condition of the pump and its ability to move enough oil to make enough oil pressure.

Good luck

[highwayman2011]

Could be oil viscosity.