Symptoms of bad harmonic balancer

Know the symptoms of bad harmonic balancer so you can replace it before it fails

The harmonic balancer’s job is to transfer rotational force to the drive belts while reducing noise from the engine’s power pulses. When the rubber isolation/dampening ring ages and hardens, it transmits more vibration to the drive belts, causing more engine vibration.vibration. Here are the symptoms of a bad harmonic balancer.

Symptom #1 Cracks or separation of the rubber isolation ring

When the isolation ring fails completely, the two-piece
harmonic balancer can come apart, throwing the drive belts off the pulley.

#2 Wobbling sound

As the rubber isolation ring deteriorates the balancer outer ring moves slightly and rotates in a wobbling pattern. This can cause a repetitive wobbling sound in the cabin

#3 Belt twang can be the sign of a bad harmonic balancer or a failing belt tensioner

Engine power pulses transfer to the belt causing it to make a twanging or guitar string sound. The longer the drive belt, the more noticeable the sound.

#4 The timing marks engraved on the outer ring of  bad harmonic balancer don’t match with the pointer on the engine

If the isolation ring deteriorates it can rotate and move the timing mark. If you set try to set your engine to top dead center

#4 Misfire due to reluctor ring movement

Many carmakers build a toothed ring into the harmonic balancer and use that ring in combination with the crankshaft position sensor. If the toothed ring chips, rusts, or is damaged in any way, the engine timing will be off. A damaged reluctor tone ring can also cause a scraping sound if it contacts the crankshaft position sensor.

Bad harmonic balancer symptom — oil leak

When the neck of the harmonic balancer sits inside an oil seal, road dirt and debris can cause a wear groove in the neck of the balancer. The groove prevents the crankshaft seal from doing its job. At that point you’d see an oil leak coming from the crankshaft seal. The fix is to replace the harmonic balancer or install a repair sleeve over the worn section.

©, 2022 Rick Muscoplat