QuestionI have a 2001 Dodge with the 24 Valve Cummins Diesel...and was curious if you know what I need to do to adjust the valves on the engine...I know you have to take the valve cover off but not sure on the proper adjustment or Clearance?
AnswerSTANDARD PROCEDURE—VALVE LASH ADJUSTMENT AND VERIFICATION
NOTE: To obtain accurate readings, valve lash measurements AND adjustments should only be performed when the engine coolant temperature is less than 60° C (140° F).
The 24–valve overhead system is a “low-maintenance” design. Routine adjustments are no longer necessary, however, measurement should still take place when trouble-shooting performance problems, or upon completion of a repair that includes removal and installation of the valve train components.
Disconnect battery negative cables.
Remove cylinder head cover (Cylinder Head Cover and Gasket) (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - REMOVAL).
Remove the crankcase breather and vapor canister (Crankcase Breather Vapor Canister).
Using the crankshaft barring tool #7471–B, rotate the engine and align the pump gear mark with the top dead center (TDC) mark on the gear housing cover (Fuel Pump Gear Timing Mark Orientation).
With the engine in this position (pump gear mark at 12 o'clock), valve lash can be measured at the following rocker arms: INTAKE 1–2–4 / EXHAUST 1–3–5. Measure the valve lash by inserting a feeler gauge between the rocker arm socket and crosshead (Measuring Valve Lash). Refer to VALVE LASH LIMIT CHART for the correct specifications. If the measurement falls within the limits, adjustment/resetting is not necessary. If measurement finds the lash outside of the limits, adjustment/resetting is required. VALVE LASH LIMIT CHART INTAKE EXHAUST
0.152 mm ( 0.006 in.) MIN. 0.381 mm (0.015 in.) MIN.
0.381 mm (0.015 in.) MAX. 0.762 mm (0.030 in.) MAX.
note: If measured valve lash falls within these specifications, no adjustment/reset is necessary. Engine operation within these ranges has no adverse affect on performance, emissions, fuel economy or level of engine noise.
If adjustment/resetting is required, loosen the lock nut on rocker arms and turn the adjusting screw until the desired lash is obtained:
INTAKE 0.254 mm (0.010 in.)
EXHAUST 0.508 mm (0.020 in.)
Tighten the lock nut and re-check the valve lash.
Using the crankshaft barring tool, rotate the crankshaft one revolution (360°) to align the pump gear mark to the 6 o'clock position in relation to the TDC mark on the gear housing cover (Fuel Pump Gear Timing Mark Orientation).
With the engine in this position (pump gear mark at 6 o'clock), valve lash can be measured at the remaining rocker arms: INTAKE 3–5–6 / EXHAUST 2–4–6. Use the same method as above for determining whether adjustment is necessary, and adjust those that are found to be outside of the limits.
Install the cylinder head cover (Cylinder Head Cover and Gasket) (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION).
Install the fuel pump gear access cover.
Connect the battery negative cables.
