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・Fair and transparent pricing

Get a quote

What others are asking

Q: Can a rear impact accident cause problems with the VSA? SYSTEM MALFUNCTIONED AFTER THE ACCIDENT

Hello, thank you for writing in. The VSA or Vehicle Stability Assist system is designed to work with the ABS system to keep control of the vehicle at all times in all conditions. It uses several of the same sensors...

Q: Knocking noise underneath car.

Hi, thanks for writing in. Diagnosing the exact source of a vibration or noise is typically only possible through an onsite inspection. However, after reading the symptoms you're describing, the two possible suspects may include the wheel bearings or the...

Q: Car owner is told squeaky brakes are normal

Hi there. Many times they say that these things are normal because they do not have a good fix for them. The brake noise problem occurs because the brakes get too hot on this vehicle and they glaze over. ...

Related articles

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...