Man Quoted Engine Replacement—Turns Out to Be Loose Bolt

After replacing the main seal of his vehicle's powertrain himself, a car owner began hearing a "knocking" noise from the engine. The first repair shop diagnosed a lower-engine failure and recommended a complete engine replacement, which could cost over $5,000. However, Twisted Automotive & Diesel in Jacksonville, Arkansas, conducted a thorough inspection and used a stethoscope to confirm there was no internal engine damage. They ultimately traced the problem to a loose torque converter bolt underneath the vehicle—one that hadn’t been secured with thread-locking adhesive. As the engine ran, the loose bolt repeatedly struck the rear of the engine, producing a knocking sound similar to a failing connecting rod. The issue was resolved simply by tightening the bolt, saving the owner thousands of dollars in unnecessary repairs. Experts advise seeking a second opinion when faced with expensive repair estimates and emphasize that DIYers should always use thread-locking compound properly and torque fasteners to specifications to avoid minor oversights leading to major misdiagnoses.