There are many moving parts that work with each other in any given situation
during the operation of an automobile. These parts are machined and designed to
slide or roll easily while working together, but when things break or wear they
can cause a grinding noise. Once you have discovered a grinding noise the cause must be identified to start the repair process. Also,
take note of when you hear the noise either when the car is cold or hot and if
any action causes the noise such as applying the brakes or turning the ignition
key. Once a grinding sound has
been detected action must be prompt to stem further damage.
Grinding Noise Causes
- Brake pads worn
- Battery needs replacement
- Starter bendix is weak
- Front wheel bearing hub is worn out
- Rear axle bearing has gone bad
- Clutch disc has fallen apart
- Parking brake shoes worn out
- Engine is grinding externally/internally
Let's Get Started!
We have listed the most common grinding noise problem in order of popularity.
The following guides feature step by step instructions, your vehicle may be a
little different but the procedures are similar in most cases. For specific
directions please ask one of our experts to be
given instructions from AllData or Mitchell1 repair manuals.
- Grinding when brakes are applied: When brake pad material wears leaving the metal backing plate to contact
the brake rotor this will result in a grinding noise being generated
from the front or rear of the car until the brake are released indicating the
brake system needs service. Also sometimes the parking brake shoes can wear
and cause grinding, to see if this is the case while the car is moving
slowly, gently apply the parking brake to see if noise changes or goes away,
if so this is an indication of the parking brake shoes needing replacement.
disc brake service guide
brake service guide
shoe service guide
Parking brake replacement
- Engine grinds when cranking over (starter): The starter will
create a grinding sound when the battery is weak and supplying too little
voltage to the starter hindering its operation, this can be tested by
performing a battery load test.
The starter uses a small gear called a "bendix" which engages into the
flywheel when the starter is in operation. When this bendix or starter motor
fails the starter must be
removed and repaired or replaced.
- Constant grind noise when the car is rolling at any speed: If at
any speed you hear a grinding noise try turning the wheel slightly one way
then the other to see if the noise changes, also apply the brake slightly to
see if the noise changes a little. This is an indication one of the wheel
bearings or bearing hubs being bad. Try to differentiate the noise being
generate from the front or the rear, right or left. You might want to have a
helper ride along in a rear seat to give a new perspective on the origin of
the grinding noise.
Front hub replacement
wheel bearing replacement
Rear axle bearing replacement
- Transmission grinds when one or any gear is selected (manual):
When a clutch disc becomes worn and clutch material is logged between the
flywheel and pressure plate it will not allow the clutch to disengage causing the
input shaft of the transmission to keep turning (usually it is stopped) this
creates a grinding noise when the gear shift is operated (clutch pedal
Clutch replacement video (FWD)
Clutch replacement guide (RWD)
- Engine is grinding while running: Typically there are two areas
an engine will grind from, internally and externally. An easy way to find
out which is to remove the
serpentine belt and start the engine. If the noise is still there the
problem is internal and if not the problem lies in one of the engine
accessories such as the alternator or water pump. Internal grinding noise
will usually include the timing chain assembly including guides and tensioner. Our experts can help you find the problem if a video of the noise
is uploaded to the question when asked.
Our team of certified mechanics is ready to answer your questions for free.
Article published 2020-11-29