Q: My car developed a very loud knocking sound.

asked by on October 29, 2016

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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I use the power windows?
Your car is equipped with power windows. Each door has a control for its own window, while the driver position has controls for all four, as well as the window lock button. The driver side window also has a one-touch...
How does the speedometer work?
Unless you’ve gone off the pavement and into the wild, you’re driving your car on a road with a speed limit. It’s important to follow those limits, not only because they’re the law, but because they help ensure your safety....
Steering wheel locking up.
The theft system on your car can have an intermittent problem of being disabled because of having other keys or metal items on your key ring. These items may be interfering with the code key to disable the system for...
Doors not responding to key fob
Hello. GM has a very lengthy technical service bulletin about this concern. The reference # is PIE0059, release date 03-19-10. They had an engineer look into the issue and it seems to me they had some low quality door latches....
o2 sensor reads 0 volts.
You may need to look at the code P0122 (https://www.yourmechanic.com/article/p0122-obd-ii-trouble-code-throttle-pedal-position-sensor-switch-tps-a-circuit-low-input-by-jay-safford) since it pertains to the throttle position sensor (https://www.yourmechanic.com/services/throttle-position-sensor-replacement) and this can affect all the drive symptoms you are having. The O2 sensor readings seem to be normal and you...
Car wont start. Over heating and green fluid all over the ground 2015 Nissan Versa
Hi there - the first task is to check out the overheating issue, which is obviously rather severe. I recommend an overheating inspection (https://www.yourmechanic.com/services/car-is-overheating-inspection) performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your...
What does check awd means in Lexus RX350
Hi there. There is more than just clearing the light to this situation; there is a fault with the all wheel drive system. This system relies on many mechanical, electrical, and computer components to operate properly and safely. This fault,...
05 Acura tl 6 spd will not accelerate
First see if engine will rev up out of gear to see f problem is engine throttle or you have a slipping transmission clutch. If engine runs good and revs normally then have the transmission clutch checked for needing replacement....
Can I use the ignition switch from a 1992 GMC pickup fora 1973 camaro
No. They have a different connector pin layout and connector.

Related articles

A Buyer’s Guide to the 2012 Chrysler Town & Country
While While the Chrysler Town & Country has been in production for over half a century, the 2012 Chrysler Town & Country is anything but old-fashioned. The model got a huge overhaul in 2011 and saw a few new upgrades...
The Best Used Cars to Buy If You’re an Interior Designer
As As an interior designer, you need to transport a great many different items, including fabric, paint and wallpaper samples and sometimes even furniture items. You probably don’t handle overly large loads very often, and when you have to, you’ll...
The Best Used Cars to Buy If You’re a Caterer
If If you are in the catering business, you need a reliable vehicle that will provide you with what you need to transport your food, linens, and other supplies. Generally speaking, you're better off buying gently used, because you will...