Skip the auto shop - Our mechanics make house calls

Q: What will cause a motor to knock?

asked by on

How do I fix this knocking noise?

My car has 18000 miles.
My car has an automatic transmission.

A: Hi, thanks for writing in. Engine knock is ...

Hi, thanks for writing in. Engine knock is typically caused by excessive clearance in the lower engine bearings (rod and main). Of course, to know for certain, a professional would need to listen to the noise firsthand. Spark knock, which is the result of abnormal combustion, can also result in a knocking or pinging noise. Loose torque converter bolts or a cracked flex plate can also do the same. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: My car is making a grinding noise

Hello. It sounds like you either have a speed sensor that is not reading correctly or you may have a transmission or transfer case issue. If this is an all-wheel drive model, then it is more than likely the transfer...

Q: Power steering issue with my car.

General motors vehicles such as your Impala are well known for having power steering issues. First, check the level of your power steering fluid. If it is low, there is a leak somewhere that needs to be addressed before proceeding...

Q: automatic transmission,will only go if i manually shift

You may have a bad shift governor in the back of the transmission. The governor will shift the transmission as you speed up. Some transmissions have a manual type and others use an electronic type. Either way, it is in...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...