Fuel System

WARNING: This page is about a different car, the 2015 RAM 3500 HD and 2015 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

A fuel system noise can be identified by one of the following conditions:

Loud knock (Rap) type sound with rough idle (vibration and smoke

This condition can be caused by one of the following:
- Alternative fuel or fuel contamination. Perform the DIESEL FUEL CONTAMINATION TEST procedure. Refer to DIESEL FUEL CONTAMINATION TESTING PROCEDURE .
- There may be air in the fuel system. This requires checking and correction.
- Fuel Injection Pump phasing may be incorrect. Check the Fuel Injection Pump phasing if necessary. To find the timing procedure, refer to PUMP, FUEL INJECTION, INSTALLATION .
- Excessive pressure in the high pressure side of the system. This should be accompanied by a fault.
- The fuel injectors may be stuck or have low opening pressure. This requires replacement of defective injectors. A cylinder cut out test or mechanical blocking of injectors (injector block off (special tool #9011, Adapter, Fuel Pressure Test)) can be used to identify failed injectors.
- If Fuel Injectors are found to be stuck or having low opening pressure, perform the DIESEL FUEL SYSTEM CLEANING PROCEDURE. Refer to DIESEL FUEL SYSTEM CLEANING PROCEDURE .beginning with Step 12.
  After performing the Cleaning Procedure (Steps 12-19), retest the injectors using the cylinder cut out test or mechanical blocking. If there is still a problem, replace Fuel Injectors as necessary.