This condition may be caused by one or more of the following problems:
| • | Loose torque converter bolts. (Retighten to specifications.) | 
| • | Exhaust leak at the manifold. (Tighten bolts and/or replace gasket.) | 
| • | Excessive rod bearing clearance. (Replace bearings as necessary.) | 
| • | Detonation or spark knock. (Refer to Engine Controls.) |