Q: My car developed a very loud knocking sound.

asked by on

I have car that developed a loud knocking sound. I don't really know what it is, I was told it could be a rod or the rocker arm but I don't know how to get to them. Can I get to it without taking apart to much of the car?

My car has 175000 miles.
My car has an automatic transmission.

It is possible the valve lifters are starved of oil due to a failure in the rocker arm. There are reported cases where the rocker dowel pins shear off. A direct consequence of that is oil starvation as the oil holes get covered. The rocker arms are part of the cylinder head assembly, so it is an on the vehicle repair and YourMechanic specialists, depending on your region, will be able to complete the work. Just to make sure that it is an internal engine noise, you can disconnect (briefly) the serpentine belt that drives all of the accessories and see if, by chance, the noise goes away (just in case it’s a failing alternator pulley bearing for example). It sure sounds like a valve lifter oil starvation issue though.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. My car developed a very loud knocking sound.

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: What is wrong with my suspension/steering?

Hi, thanks for writing in. If the struts on the car are original, it would not be unreasonable to replace them outright simply because you have relatively high mileage on the car. While the struts are being replaced, all other...

Q: Have a Chrysler 200 2014 with a 2.4l engine, have the etc light and engine light on, there is a clicking coming from throttle body

Hi There, The red lightning bolt indicates that there is a problem wit the electronic throttle control unit. This may be for a specific reason or may be due to a slight glitch. Try resetting the throttle control unit by...

Q: Hi Patrick i seemed to have bottomed out my m35 and need to replace oil pan and gasket. How much is the cost??

I would first recommend having the engine and under the vehicle inspected to see what all got damaged. If you damaged the oil pan then it may have also damaged the exhaust or subframe under engine that may affect the...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
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...