Skip the auto shop - Our mechanics make house calls

Q: Knocking noise coming from engine

asked by on

Ok my car has a loud knocking noise coming from it I was told I need a new engine

My car has 179000 miles.
My car has an automatic transmission.

A: Hi and thanks for contacting YourMechanic. ...

Hi and thanks for contacting YourMechanic. If the engine runs okay and has a little vibration with a loud knocking noise, and the oil pressure is low at idle and high when above idle, then you have a rod knocking from a failed or burned rod bearing. If this is the case, drain out the oil and remove the oil pan; then remove the rod bearings from the rods - I recommend replacing all of the rod bearings, even if they don't look that bad. The bearings can be replaced with the engine still in the car. Once you have replaced all of the rod bearings, make sure that you torque all of the rod bolts or nuts to the manufactures build specs. Then put the oil pan on with a new pan gasket and a new oil filter. Put in new oil in the engine and start the engine. If the knock goes away they the problem is fixed.

If the knock continues, then you have a piston that is coming apart and needs replacing. If the engine has a vibration afterwards but there is no knock, then the valve train on the cylinder heads are bent and causing a minor misfire.

Problems with engine noise can be symptoms of serious issues, so a certified YourMechanic technician can be dispatched to your location to inspect your engine knocking and provide you with a second opinion or assist you with any repairs.

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: Car overheating; thermostat

Hello! A common reason for most vehicles to overheat is a faulty thermostat. However, on 350Z's, the factory fans are known to fail prematurely and cause an overheating scenario. I suggest checking the performance of the cooling fans and thermostat....

Q: steering failure.

If the inner tie rod were to break or come loose, there is a chance steering the vehicle would become very difficult. Hire a technician to inspect the previous work done as well as check for new damage that may...

Q: On highway engine revved, accelerated and pedal stuck

Hello. The transmission itself will not cause the engine to over-rev like this on your 2013 Acura ILX. It sounds like you either are having a failure in the throttle body or you may have a computer issue. I...

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...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...