This TSB applies to a host of Chrysler vehicles including 2001-2004 Sebring/Stratus, 2002-2004 Jeep Liberty, 2002-2004 Cherokee, 2003-2004 Neon, 2001-2004 PT Cruiser, 2001-2004 Voyager, 2001-2004 Town & Country and 2003-2004 Wrangler, equipped with the 2.0L, 2.4L DOHC or 2.4L turbo engines.
An irregular “snapping” sound may be heard at the passenger-side of the cylinder head. The sound may be noticed when the engine is idling in Park between idle rpm and 1,400 rpm at normal operating temperature. The sound is irregular, not periodic or harmonious. The frequency of the sound will increase with rpm. The sound is more of a higher-pitch “snapping” noise, not a low metallic knock.
The sound is likely the result of improper machining of the camshaft bearing cap bore radius on caps L2 through L5 and R2 through R5.
- Remove the cylinder head cover.
- Remove one camshaft bearing cap at a time, and lightly chamfer the bore radius edges with a small hand file, creating a 45-degree chamfer that is 1.0 mm to 1.5 mm in width along the bore radius of each cap’s bore edge. Be careful not to scratch the bore surface of the bearing cap. DO NOT LOOSEN OR REMOVE THE FRONT (R1/L1) CAP OR THE LEFT REAR L6 CAP!
- Reinstall each cap and loosely install the cap’s bolts. Prior to and during torquing each fastener, twist the bearing cap by hand in a clockwise direction, as viewed from the top of the engine. Torque M6 fasteners to 105 in.-lbs., while maintaining a clockwise twisting force on the bearing cap.
- Perform this procedure for each cap (L2, L3, L4, L5, R2, R3, R4, R5 and R6, one cap at a time.