08/02/2026
2004 Honda Civic Timing belt replacement.
Cause: customer stated the engine sounded like it had no compression.
Diagnosis:
Verified low compression on all cylinders, measuring approximately 60 PSI. Removed the upper timing cover and found the timing belt had jumped one tooth. Removed the timing belt and tensioners and found the timing belt tensioner had no spring resistance, indicating an internal spring failure.
Installed a new timing belt and tensioner, then attempted to start the engine. Compression remained low on all cylinders. Added approximately one teaspoon of engine oil to each cylinder and repeated the compression test. Compression increased to approximately 150 PSI on all cylinders, indicating the cylinder walls had been washed down with fuel and the piston rings were not sealing properly.
Removed all spark plugs and cranked the engine to purge the excess fuel from the cylinders. Once the cylinders were cleared, applied a small amount of starting fluid to assist with initial combustion. The piston rings reseated, compression returned to normal, and the engine started successfully.
Correction:
Replaced the failed timing belt tensioner and timing belt. Cleared excess fuel from the cylinders, restored cylinder sealing, and verified proper engine operation. Vehicle now starts, runs, and drives normally with no further concerns at this time.
