Are the two oil pressure relief valves on certain Navistar engines interchangeable?
The AERA Technical Committee offers an oil pressure relief valve caution on 1997-2004 Navistar 466E and 530E engines. These engines utilize two oil pressure relief valves in the engine and proper location is important. There are two locations that use these valves, one is the side of the block and the other is the front of the engine. The valve that is located on the side of the cylinder block is actually called an oil pressure regulator and the one located in the front of the cylinder block is an oil pressure relief valve. Simply by looking at them, it may be difficult to figure out which valve is which. Both valves look identical and can be easily installed in the wrong location. When looking at the valves, there should be an “FC” stamped on the face of the valve, which indicates that the valve is the oil pressure relief valve and should be installed in the front of the engine. The other valve is the oil pressure regulator valve and should be installed in the side of the cylinder blo
