Download ISSUE Some vehicles equipped with a 6.0L engine may exhibit a diesel odor in the cab. ACTION It may be necessary to replace the exhaust manifold gasket. Refer to the following Service Procedure. SERVICE PROCEDURE 1. Start the engine and warm it to normal operating temperature. 2. Remove the exhaust pressure (EP) sensor. NOTE SOME BUBBLING OF MOISTURE/SOOT BETWEEN THE EXHAUST MANIFOLD AND HEAD WHEN THE ENGINE AND MANIFOLD ARE COLD IS NORMAL. ONCE THE ENGINE AND MANIFOLD ARE AT OPERATING TEMPERATURE, THEY SHOULD BE SEALED. 3. Using the Rotunda Smoke Machine (218-00001) induce smoke into the EP tube. Inspect for leaks around the exhaust manifolds and y-pipe. If a leak is found at the exhaust manifold, replace only the exhaust manifold gasket that is leaking.