Inspection After Removal
WARNING: This page is about a different car, the 2018 Nissan NV3500 HD and 2018 Nissan NV2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
Oil Cooler
Check oil cooler for cracks. Check oil cooler for clogging by blowing compressed air through engine coolant inlet. If necessary, replace oil cooler assembly.