Q: Experiencing a knocking noise while I'm decreasing speed on the highway. I have examined the up&lower ball joints, tire rods, axle

asked by on January 05, 2017

Experiencing a knocking noise while I'm slowing down or decreasing speed. I have examined the CV axles, tie rods, upper and lower ball joints and everything seems to be in place. Does not make no squeaking sound like a ball joint would. And no noises when turning left or right. The knocking sound appears to be coming from the driver's side while decreasing speed at stops on straight roads.

My car has 135000 miles.
My car has an automatic transmission.

Hello, thank you for writing in. Inspecting the suspension and steering components was a great idea. Did you perform a visual inspection, or did you actually raise the vehicle and maneuver the parts to check for excess play? However the brakes and the drive shaft can both causing a clunking noise when coming to a stop. Attempt to replicate the noise while backing up. If the brakes are of a concern, you will likely hear it in both directions. Something like your drive shaft may not be heard while backing up. Most of these components can be tested while on the vehicle, but you may need a hand. For more diagnostic help, contact our service department.

Was this answer helpful?

Hi there. Check the brake system and see if the caliper or rotor is damaged on the driver side wheel. Since the noise only occurs when decelerating to a stop, then there could be an issue with the brakes. Try downshifting the transmission on a road with no other cars and let the vehicle decelerate as the transmission slows down the vehicle without touching the brake pedal. If there is no nose, then the brakes is your problem. If the noise is still there, then either there is a loose suspension part or there is a problem with the transmission. Check all the fluids on the vehicle and make sure that they are full and top off any low fluids. If you cannot locate the issue that is making the knocking sound when decelerating, then I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose the issue.

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

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

Master cylinder losing fluid and I can't find leak.

It is possible that your brake fluid could be leaking into the power brake booster. This is the big round container that the master cylinder is bolted to. The brake booster operates off of the vacuum created by the engine...

I replaced thermostat and thermostat sensor hose collapsed and I just changed the upper radiator hoses but haven’t tested it if it

Radiator hose collapse is from a leaking intake manifold gasket or radiator cap is bad and not letting the system draw fluid from overflow. Replace the cap and pressure test system to see if it has a leak in the...

What does a vehicle speed sensor look like?

There may be a couple of things going on at the same time here. Is the Check Engine Light on? A vehicle speed sensor problem may illuminate the Check Engine Light if the lack of signal is causing shifting errors....

Related articles

How to Troubleshoot a Clicking or Popping Sound in Car Wheels
Car wheels make popping or clicking noises due to faulty CV joints, worn struts or drive belts, loose hubcaps, cupped tires, or loose suspension.
How to Troubleshoot a Car Exhaust or Engine Noise
Car exhaust systems and car engines make whirring, clicking, or sputtering noises if there's a faulty belt, alternator, water pump, or tension pulley.
Symptoms of a Bad or Failing Cruise Control Vacuum Bleed Switch
Common signs include cruise control disengaging on its own or not disengaging when the pedal is pressed, and a hissing noise coming from the dash.