When people are describing the unusual noises they hear under their Jeep Wrangler we often hear them say that they hear a knocking noise when they are accelerating. They always want a quick answer to what could be causing the knock.
There are many things that can create a knocking sound when you accelerate.
Let’s take a look at some of the most common reasons for a possible knocking sound to be heard when you accelerate.
What Is Causing The Clunking Sound on Acceleration?
My first question when I am asked about the knocking sound causes is where were you driving when you heard this noise? This often causes people to get confused looks on their faces.
The road surface you were driving over may play a huge part in the noises you hear from under your vehicle. A rough road can jar and jostle car components enough to make them brush against other things and the result is unfamiliar noises. By the way, a series of speed-bumps like you encounter in some subdivisions or mobile home parks can do the same thing and cause you to hear strange noises.
The second question I ask everyone who wants to know why they are hearing a knocking noise when they accelerate is how often they have heard the noise, or sometimes I ask them when did you start to hear this noise?
The length of time a noise has been happening can tell your mechanic a lot about the vehicle, how you drive, and where to look for the cause of the problem.
Exhaust System Hangers
The clunking sound you hear could very well be the hangers and connectors on your exhaust pipes and system starting to wear out.
The rubber tips and bushings on these hangers can start to deteriorate with age. Rubber starts to crack and break down over time and especially when it is exposed to extreme temperature variances, wet conditions, dirt, grime, and the heat produced by the vehicle exhaust.
At some point, the rubber that should stop the metal fastening devices from rubbing against the metal vehicle frame and the pieces of the exhaust pipes, muffler, etc., wears out and the rubbing, clunking, grinding, whining noises begin to be heard under your vehicle.
When you accelerate the car speeds up and the exhaust pieces vibrate more so the noise is intensified. When you drive over rough roads and surfaces the same thing happens.
If the tires on your vehicle have gotten out of balance they could be why you are hearing knocking noises, clunking noises, and a lot of other noises. Unbalanced tires do not roll smoothly like properly balanced tires do. That means that when the unbalanced tire rotates things are jarred around and noises are heard.
Check the tires of your vehicle and see if they are unbalanced, or if the tread on them is wearing out more on the inside or outside instead of evenly across the entire tire. When you are doing this check you may find the tread wear pattern to be different on just one tire, or to be different on the front but not the back.
The uneven tread wear pattern is an indicator of unbalanced tires, tie rod ends that are wearing out, ball joints that are wearing out, and u-joints that are wearing out. If you see uneven wear on your tires then you have to take the time and discover exactly what component is causing this problem.
It may be faster and easier for you to visit a tire shop and let them evaluate the vehicle and tires. They can lift the vehicle up so that they can stand under it and closely examine every component.
While lifted they can try to move the tires and see if the ball joints, u-joints or tie rod ends are holding in place. They can inspect CV joints and the boots and bushings on everything to determine if the rubber boots have been compromised and is allowing dirt and sand to get inside.
If your engine gets low on oil or runs out of oil, a knocking sound may be heard. The knocking sound is the result of the internal components not being able to freely and smoothly move up and down and keep the engine running.
If your knocking sound is caused by low engine oil levels you may very well be looking at some serious engine damage to the heads, the pistons, or the rings. You need this kind of knocking sound to be evaluated by a professional so you can be certain that the root of the problem and all consequences of the problem are found and corrected.
Frequently Asked Questions
Does A Knocking Sound Mean A Blown Engine?
Hearing a knocking sound does not mean a blown engine, but it can mean something is seriously wrong with the vehicle. If you hear a knocking sound investigate thoroughly before driving the vehicle very far.
Can I Change My Own Ball Joints?
You can change your own ball joints if you have a little mechanical knowledge. Remember that you might need a press to get the new ball joints in place. If you do not own a press, you can probably rent one.
How Far Will A Vehicle Driver With A Broken Tie Rod End?
There is not a set number of miles that the vehicle will travel on a tie rod end that is breaking. Once that tie rod breaks the vehicle is not going to be drive-able until the tie rod end is replaced.
Knocking sounds are warning signals that something under your car or in your engine is not working properly. Do not turn up the radio and ignore these sounds. When you hear any suspicious noise take the time to check out possible causes or take the vehicle to the shop and let a professional go over it for you. The warning knock may be your chance to fix a problem before it becomes a catastrophe.
Other Jeep Problem Solution Articles
1. What Causes a Jeep to Have a Strong Antifreeze Smell?
2. Tow Dolly – Can I use one to Pull My Jeep Wrangler?
3. Is an Alignment Necessary After Installing a Lift Kit on a Jeep?