Q: Knocking sound in engine when clutch is up

asked by on June 14, 2016

When the clutch is up, there is a knocking sound in the engine. When the clutch is pressed down, the knocking sound goes away. The car pulls slightly to one side and there is a growling noise when I change gears and accelerate and it shakes into idle. Several months ago the clutch was changed, but it still feels rough in the pedal. I’m wondering if the mechanic only changed the clutch and did not change the dual mass flywheel. Or it might be a release bearing, which hopefully I could change myself without the clutch or do both have to be changed at the same time?

When the clutch is replaced, generally the clutch disc, pressure plate, throwout bearing, and pilot bearing are all replaced. These usually come in a kit, and when they are replaced, the flywheel is usually refinished based on need. If the throwout bearing has failed, it usually makes noise when the clutch pedal is pushed in but not when it is not pushed. Common causes of this would be a failed axle shaft, CV joint failure, or suspension failure. A qualified technician, such as one from YourMechanic, would be able to diagnose this knocking sound and perform any repairs required.

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