Worn or otherwise compromised drive belts are a common cause of noises when accelerating. backyardmechanic. Every car has a unique noise, and you will accustom to these noises with time. This sound will usually be louder with the windows down. Jul 15, 2022 · To help prevent engine knocking when accelerating, it’s important to maintain your vehicle’s engine in good condition. Whistling. Ford Mondeo mk4. Knocking Sound Under Car When Accelerating, Causes #6: Rod Knock Aug 15, 2019 · Wrong Octane/Bad Gas. Makes no noise when not accelerating and at idle. But when it is warm, not cold, I get a mild knocking sound when at the lower RPM range. On a transmission, this could mean: Worn or damaged output shaft rear bearing. Aug 17, 2023 · Sound #4: Roaring Noise When Driving. I have the same issue. Nov 10, 2017 · Q: Knocking noise/rattle underneath my car when I accelerate about 2000rpm-3000rpm and stops after the trans shifts. With an exhaust leak, the muffling of the noise is cut short, making the noise louder. Aug 10, 2023 · Check the Exhaust System. When the fuel grade is below manufacturer’s specifications (e. Transmission Makes a Growling Noise While Car Is Moving. A faulty exhaust system can cause loud engine sounds while accelerating. Step 2: Check the engine knock sensor. It’s not recommended to drive with engine knocks as it may pose more problems, such as engine seizures. com http://1aau. Clicking. 1000 to 2000 RPM. This can cause a detonation knock in the car engine. These sounds can mean that your belts have worn out or that one might be slipping due to a loose tensioner. This happens when I start to accelerate from a complete stop or under 40 mph when I accelerate somewhat hard. (This is called “pinging. Worn muffler: A damaged or worn-out muffler can produce a rumbling or growling noise. Over time, rubber materials wear down, especially when stressed. A failing water pump. However, if the knock sensor is not working, spark timing will not retard when it should. Running rich - which means too much air is in the combustion chamber - is a major cause of engine knocking. If a thin whistle or a knock small in intensity is heard from the front of the engine compartment, then the water pump is faulty. The first thing you should do when diagnosing engine knocks is to check the oil level and refill it if necessary. 10. The Back Tires Could Be Misaligned. What’s happening: You probably have a leak or crack in your exhaust system. Jan 13, 2023 · What Makes a Clunking Noise When Accelerating in a Car or Truck. At the other end of the spectrum, it could be worn out or loose rod bearings, timing belt problems, or your engine preparing to seize. May 19, 2010 · I have a 2008 2. When brake pads become worn or loose, they can make a squealing, scraping, or grinding sound while the car is in motion. Nov 15, 2023 · Keep reading for more information about what might be causing a knocking noise under your car. When the air and fuel mix is wrong, the fuel explodes in the cylinder instead of burning smoothly. Keeping the fuel system clean by using fuel additives or having the system serviced. I know the NA advertised unleaded regular but it also states that light knocking while accelerating or driving up a hill is normal. Therefore, you should get them realigned now and then, especially when installing new tires. Uneven wear: A clunking noise may arise due to uneven tire wear, leading to poor acceleration. Step 4: Check if plugs are cracked around the tip. Damaged Serpentine Belt. Hi my jeep commander has an ugly knocking noise coming from under the center console, it’s mostly when I start accelerating and i have to let off the gas so it’ll stop then accelerate again. Check the inner and outer CV boots on both front left and right sides. e. #1 · Sep 2, 2014. When this system is compromised, you get loud engine sounds. Check for any leaks or cracks in the exhaust pipes. 5 (facelift) 2. an 85 rather than an 87), many older engines will begin to knock at a relatively rapid pace. Don't be fooled by detonation. Low engine oil level. Apr 1, 2022 · When you brake normally you hear either 1 knock or mainly 2 knocks, one from each side of the car at the wheels, when you pull away, you get 1 knock or 2 knocks in the same way like something is releasing i. Another possible cause of noise when accelerating from a stop is worn out spark plugs. I thought maybe it was from using lower octane fuel, so I tried premium and it is still there. Jun 13, 2018 · Common reasons for knocking and squealing from your vehicle’s suspension Your vehicle’s suspension is made up of several different components that help absorb shocks, brake, and turn. Detonation Knock: Bad Timing. The solutions include changing the suspension Jan 14, 2023 · 2. This reduces power a bit, but protects your engine against detonation. g. The first issue that causes a rattling noise underneath your vehicle is a bad catalytic converter. If you've heard this noise, proceed to figure out what exactly is wrong. 3. The knocking can be caused by a variety of factors, including poor fuel quality, incorrect fuel octane rating, or a malfunctioning engine component . If you hear the noise, it's almost certainly internal engine issues. If the knocking is regular, I agree with 8R6 that the axles are a potential candidate. A squealing sound from under the bonnet of your car is one of the most common – and easily fixed – car sounds. If you hear a knock or other odd sounds coming from below, the culprit is usually one of three parts of your system – your tie bar, ball joints or sway bar. If you’re taking a tight turn at low speed and your car is making a grinding noise, which could mean that your CV axle (which connects the wheels to the transmission) is damaged or worn out. When there’s too much air and not enough fuel, the mixture is considered “lean. Loose or broken bolts, nuts, and washers that hold the driveshaft together. Transmission Fluid. I first noticed the knocking about two years ago. Several potential knocking sound under car acceleration causes could be loose exhaust components, worn engine mounts, or damaged suspension parts. That would be called spark knock. If they wear out or break, it will knock when not accelerating or braking. Mar 14, 2023 · 1. A normally functioning belt turns smoothly when the engine runs. Volvo Mechanic: Ryank. Damaged Suspension Components. snapchat. Be sure to check your owner's manual to find out what octane rating is right for your car. Worn Wheel Bearings – These are the bearings that allow your wheels to rotate smoothly. Overall, there could be many reasons for bad engine timing. In order for your engine to run smoothly, it requires a precise balance of air and fuel in the combustion chamber. Jul 16, 2023 · Knocking Noise While Accelerating. This is caused by the fuel not burning fully in the engine cylinders. So, if you put regular unleaded in your car that demands premium fuel, this could be the source of your knocking sound. It sounds like it’s coming from right in front of the driver. From my point of view, the noise is coming from the driverside. Mar 11, 2024 · Manufacturers make rubber bushings. Oct 30, 2023 · If your vehicle is producing a clunking noise during acceleration or deceleration and is of a RWD or 4WD configuration, you might want to perform a thorough U-joint inspection. The only thing I can think of right now without out getting under it is a bushing/ connector in the front end. May 28, 2022 · If you’re hearing a knocking noise when accelerating your car, there are a few possible causes. The most common cause is low octane gasoline, but other potential causes include dirty or clogged injectors, defective spark plugs, and worn-out engine parts. On a transaxle, this could mean: Worn or damaged output shaft rear or front bearings. There is noise coming from the somewhere through either the transmission / clutch / gearbox / drivetrain when accelerating hard. These couplings are actually rubber doughnuts, with steel couplings for attachment to the transmission and driveshaft, transmitting power to the rear differential. com/add/naturalleanedTwitter: https://mobile. One of the most obvious signs of engine knocking is a knocking or pinging noise coming from the engine. Oct 16, 2023 · When you have a lean air-fuel mixture, engine knock can occur. Exhaust Leak. 9. Read: 6 Reasons Behind Rattling Sound in Engine When Idle. Jun 9, 2024 · 1. If you brake very gently to a stop it doesn't knock. Weird part was as long as I was already moving more than maybe 10mph I could hammer the throttle and there would be no noises or vibrations. It click's when I tapp the accelerator in very low speed, and from a standstil to back and forward. Engine knocking noises can also be caused by: Connecting rod bearing failure. Mechanic 1 says anti roll bar or ball joints. Jan 7, 2023 · Step 1: Listen for knocking sounds. May 7, 2024 · Step 3: Disconnect the spark plug wire and remove one plug at a time. Advanced ignition timing doesn’t mean it’s high-tech! If the spark plug ignites the air-fuel mixture too early in the piston’s stroke, then the timing is too advanced or occurs too soon. A more distinct knock is routinely attributed to worn rod bearings. In extreme cases, the whining could indicate that there’s a larger problem with the transmission that needs attention. It generally sounds like a low-pitched thudding noise that varies according to the rate at which you drive. 1. Here's what can cause a clunking noise when accelerating. There are no warning lights on the car, nor is there a noise until I get over 50 mph. Loose serpentine belts may cause the loud noise you hear while accelerating. Jun 6, 2017 · Clicking sound when accelerating. 4 Timing Mishaps: Engine Knock as a Sign of Timing Troubles; 1. Dec 18, 2020 · I need some input- my 2018 crosstrek has been making a rattling or knocking sound when I accelerate between 1500-2500 rpms between 30-60mph. 5x. Several components impact the air-fuel ratio, the fuel pump being one of them. Read here for more information. Engine knocking could indicate different issues, including low engine oil levels and engine bearing failure. It is loud enough that I can hear it clearly over the radio. Strange as it may seem, exhaust leaks can cause Oct 31, 2016 · This problem is most likely caused by a rapidly failing driveshaft coupling (or "guibo"). May 25, 2021 · An engine has a lot of moving parts, and a car making loud noise when accelerating could indicate engine problems. If the sound was not present before changing the tires over to the snow tires Oct 31, 2017 · This noise is more noticeable on acceleration because the engine is working harder, making the noise louder. Jan 27, 2017 · Andygg65 said: Im having a problem when accelerating hard. Mar 10, 2023 · Here are a few of the most common reasons why engine knocking may appear when idling but go away when the car accelerates. My 2011 2. D. Worn Axles. Nov 7, 2021 · CAR HAS TICKING SOUND NOISE WHEN ACCELERATING OR REVVING UP, TICKING TOP ENGINEIf you hear a ticking noise coming from the exhaust manifold on your car in th The exhaust system manages gases from the combustion cycle and muffles the noise your engine makes. Jul 15, 2023 · I haven't have this issue but i think before you replace this, you should check to know exactly where is the noise coming from and how it looks like as engine noise, brake noise or accelerating noise. Quite often knocking noises become more apparent when you are accelerating. Jan 23, 2014 · 01 In order to remove the axles, you need to first drain the oil, remove the cover, and remove the Spider gear “pin. May 6, 2022 · Reason #1: Worn Motor Mounts. The wheel could be loose and moving around. My car has an automatic transmission. to/c/104/au/engine-mountDo you hear a clunking noise in your car or truck when you accelerate, or shift gea 10. It could also mean a whole host of things inside the gearbox. The noise mainly comes from rubbing parts or elements. Serpentine Belt Issues. Cars make noise under normal operation. Dec 18, 2023 · Common Causes. Slapping noises when accelerating usually mean a tyre is flat or under-inflated. Mechanic 2 says nothing wrong with roll bar or ball joints but rather its the driveshaft by exclusion since the sound only comes when driving. There are also some more technical causes to point out As in the title a knocking sound when NOT accelerating, both in neutral and in gear, the knocking frequency increases with the speed. There are various reasons why your vehicle’s engine may be producing a knocking sound when decelerating. Consequently, you may hear a pinging or rattling sound (spark knock). Step 7: Reinstall all plug wires. Sep 14, 2022 · These sensors are the ones that monitor the position of the camshaft and crankshaft. ”. A noise that can’t be heard at idle can make itself known when the motor is under stress. The noise will usually occur when the engine is first started, hot or cold, before oil pressure builds up. Jan 3, 2011 · A single knock/bump when accelerating from a stop. Like, Comment, Subscribe MechanicsLuvClassicsSnapchat: https://www. It can be an issue as small as bad-quality fuel that causes an engine knocking sound. One of the most common reasons for an engine knocking at idle is a lack of sufficient engine oil within the engine. This includes: Regularly changing the engine oil and using the recommended grade and type. A lean mixture can cause the fuel Compare spark plug replacement prices. Jan 7, 2023 · This whining noise can be caused by a bad serpentine belt, a boost leak or a vacuum leak. It’s possible to find where your exhaust is blowing, provided you do so carefully. Nov 13, 2014 · Two that are GM dealers. If you need to be using premium fuel, use it. Tires affect every car’s mobility. See how much you can get for your damaged car now . Slapping. Its a single knock when letting off the gas or when punching the gas. This one really needs a mechanic’s attention. When your exhaust system fails, all of your It idles quietly, and can drive under 45 mph. Can feel the knock in the pedal/floor. Step 3. Step 5. Jul 21, 2012 · My original problem was any acceleration from a dead stop with more than 1/4 throttle made a horrible thumping sound. Conclusion. Car runs good. A squeaking or squealing sound when you're accelerating or cruising can mean there's a problem with a drive belt on the engine. This noise is usually heard in any gear while the car is moving. When I continue to accelerate,it goes away and does not come back when slowing down to a stop for example. 6 Rattling Rods: Worn Bearings Can Cause Your Car To Knock; 1. 4L Patriot Latitude 4x4 has been making a knocking noise when I accelerate for the past while. The knocking sound becomes louder and faster as you accelerate. I haven't had a chance to look under the truck yet, but last week I noticed this sound. It could also be due to a power steering issue, worn bearing or low engine oil. Old Spark Plugs. Easiest way to check engine versus suspension noises: Put the car in park (or neutral with an MT and press in the clutch), turn on your e-brake, keep your foot on the brake pedal, and rev the engine up slowly. I have the same described coin in the can sound on my 2010 2. #1 · Mar 29, 2021. Step 5: Clean the spark plug hole and around the threads. twitter. Do you hear a knocking sound coming from your car’s engine when driving? If so, it’s possible your vehicle has a rod knock. When an exhaust blows, the gases leak out somewhere before the tailpipe. sticking calipers. Bearing Wear : Worn or damaged bearings in the drive shaft assembly can contribute to a rumbling or grinding noise, especially when accelerating. Hi there. Lean Airfuel Mixture. In this case, you need to check it, and if that is the problem, replace it. Sep 12, 2017 · 1 post · Joined 2021. Squealing. Sounds like its coming from drivers side. Oct 20, 2010 · knocking. 3L Mazda 3 5-speed manual trans 16,000 miles hearing the same problems at 1800 - 2000 rpms under load. Jan 24, 2014 · Loudest when the engine is under load or acceleration, crankshaft knock can be diagnosed by paying close attention to the specific type of knock: A regular, rumble-like knock is often from worn main bearings. https://www. 0 tdci 6 speed. The axles are the shafts that connect the wheels to the transmission. 3 Bad Spark Plugs Cause Your Car to Knock: Silent Saboteurs; 1. Sep 2, 2014 · 59 posts · Joined 2013. Perhaps check the mount anyway just because it is 'easier' to do and rule out as a contributing factor. Air/Fuel Mixture Too Lean. The car had two soft tires on the driver's side for a few weeks, I had them May 22, 2024 · Loud Engine Noise Under Acceleration – Normal, Just Noisier. When you detect white smoke from the exhaust when accelerating or even during start-up and warm-up, this indicates that your vehicle’s engine is absorbing too much transmission fluid from the vacuum hose or line, resulting in burning oil and a noticeable burnt smell. A Teeth-Rattling Grinding Noise That Becomes Worse As You Accelerate. The back tires tend to get misaligned over time, and when they do, they tend to move sideways, thus resulting in knocking noise coming from the back of the car when driving. The knocking sound is noticeable when you drive slowly e. Knock Sensors (KS) Bolted To Engine Block. My 2012 Outback ,4cyl with 160k miles generates a rattle/knocking sound when first accelerating or driving at low speeds while slightly accelerating. Happens from using low octane fuel. I've seen some others posting online about this issue from the past with other Audis, but no one ever got to the bottom of it. I have been hearing a knocking sound for the past couple of weeks when I accelerate from a stop or low speed. Nov 21, 2022 · Loose Components: Loose connections or mounting points for the drive shaft can result in a rattling or knocking sound when the vehicle is under load during acceleration. They’ll sound like a ticking or Feb 23, 2024 · Engine knocking is a common problem that occurs when the fuel in your car’s engine detonates prematurely. Jan 22, 2022 · You may be able to hear these sounds through the floorboard, and you might feel a slight vibration near your feet. Mar 20, 2024 · 1) Lean Air-to-Fuel Mixture. Just beware of this. The noise takes a while to begin, after the first drive of the day, probably because the faulty part needs to heat up (and expand) before getting loose and start rattling. The moment you notice a strange noise from anywhere around the car, it’s a sign of a faulty system component. This allows you to push the axles inward, so the c-clips can be removed . A blowing exhaust can cause the engine to sound louder under acceleration. All fluid levels ok. My car has 156000 miles. Apr 28, 2019 · Good to find this thread. Broken Belt. Bad fuel pump. A vehicle engine, for instance, makes a little hum sound when the engine is running. Yes, that sounds like the propeller shaft. A bad serpentine belt could be a culprit of knocking noises. The roaring you hear is excess engine noise that would normally get silenced by the muffler. 5. Happens more often when it's a jerky acceleration/decel. Low Octane Rating. Low engine oil can lead to knocking. If they wear out, they can often cause your car to shake. Final Thoughts. 4086 posts · Joined 2008. A common cause of a clunking noise while accelerating or decelerating is worn motor mounts. Like. Firstly, a knocking sound that happens while slowly accelerating could be harmless. For instance, worn valves can make a clicking noise that’s more noticeable the faster a vehicle moves. Overly Advanced Ignition Timing. Jul 22, 2023 · Wheel bearings: A single clunk when accelerating might be caused by worn or damaged wheel bearings. When accelerating after just starting up the car, at about 20 miles/hr the gas pedal feels a couple of clicks. When it malfunctions, not enough fuel reaches the engine, causing it to knock. And from somewhere in the suspension/driveshaft aerea. Now let’s move on to the next probable cause of the knocking sound under car when accelerating. I thought it might have been my rear end and even started a thread about it. This makes the knocking sound. I don't hear it while in neutral and revving the engine, but when accelerating in gear from a stop I hear The wrong blend of fuel and air can cause multiple ignition points, creating those knocking noises you can hear. Staying on the theme of combustion, the “spark” provided by the spark plugs ignites a compressed air fuel mixture. On a stick-shift car, it can be something as simple as a clutch adjustment. What you hear: A loud roaring sound coming from somewhere underneath the driver’s seat. If your engine sounds louder under acceleration, you could have a blowing exhaust. I am including a video of what it sounds like. CV joint. Aug 17, 2022 · The most common cause is dirty or clogged fuel injectors. Only does it cold and when driving. org/what-makes-a-clunking-noise- Shop for New Auto Parts at 1AAuto. Higher octane gas might help, but it's not good for the car to drive in too high a gear. First thing, put the car up on a hoist Aug 10, 2023 · And, cause the (PCM) to retard timing. Replacing spark plugs and ignition components Apr 16, 2019 · Some common suspension problems that can cause your car to shake and vibrate include: Worn Ball Joints – These are the pivot points between the suspension and the wheels. #1 · May 6, 2020. When the belt stretches or goes bad, you'll hear a rattling noise as you're driving. It stops when I’m going faster on the freeway and doesn’t happen when I’m idling. It happens even if you lightly touch the gas to accelerate. It is best to have a professional inspect your vehicle to diagnose Nov 5, 2023 · Locate the loose mount or bolts. Can some help identify the issue? It happens in the low roms between 1500 to 3000 roms and then you Jan 24, 2024 · 10. It's a Performance with 20" wheels, so no wheelcap. When accelerating, squealing or squealing usually indicates a problem with the belts; however, if the noise occurs at low speeds or when applying the brakes, it is likely the result of a problem with the brakes. It only occurres when starting from a complete stop and at no other time. Mar 29, 2021 · 26 posts · Joined 2020. Using fuel with the proper octane rating is essential. — #1. Replacing or repairing an engine is one of the most costly repairs for any vehicle. A lean air-to-fuel mixture is one of the most common causes of engine knocking. In case of a missing bolt, replace the bolt and fasten it tightly. moving off and under 30 mph but you can't hear anything when going fast. U-joints allow a vehicle’s driveshaft to achieve the appropriate inclination, between the transmission and differential. It's a little hard on the motor. Noise only happens when giving it gas (under load), when letting off the gas, noise goes away. Its sounds like pinging / a gerbil running in it's cage. It is probably normal for that car. Bad fuel can cause your Equinox’s engine to knock. If the sound comes from beneath your vehicle, it is probably the transmission. So I just barely noticed this but whenever I accelerate I hear kind of a weird grind noise. Test the vehicle to see if you hear the knocking noises when it’s coasting. I was told it was a chain from inside the transmission or something wrong with the 4x4. This movement can cause the engine to hit other parts of the car, resulting in a clunking noise. It is also possible to find where the exhaust is blowing, provided you do so carefully. Dec 7, 2014 · cipher93. The wrong fuel can also cause a knocking sound. If your motor mounts are worn, they may not be able to properly support your engine, causing it to move around more than it should. For instance, you might have loose cargo inside your trunk or something rolling underneath your seat inside the car. Alternatively, a component might That is probably knocking, or premature detonation. When these joints wear, they often chatter or Aug 25, 2013 · A failed front mount could allow the engine to be moving back and forth during acceleration resulting in the noise. It's likely that you should be in a lower gear or ease off the throttle whenever you hear it. This sound is usually louder when the engine is under load. The sound will cease when I slow down, and I won't hear it until I go around 50 mph again. If you hear clicking or rattling under the hood, there may Jul 2, 2022 · A cracked or broken case on the driveshaft housing. If left uncatered, these issues can result in engine damage. and I have gotten 3 different answers, from its normal to it needs a high pressure fuel pump. The most common reason why your engine is knocking during acceleration is you have the wrong fuel in your car or just fuel with a low octane rating. A knocking sound is a backlash appearing from the natural wear and tear of car parts and other technical errors. A whistling from under the bonnet might mean your engine has a vacuum leak from one of the hoses around the air intake – these can be tricky to trace, but are usually simple to fix. A sharp, irregular knock can be from a worn crankshaft thrust bearing. Engine Knocking. It could be from: Exhaust leaks – A hole in the exhaust system such as a muffler or exhaust pipe or a leak in places like the exhaust manifold can cause a significant increase in noise. #6. May 4, 2023 · However, if the knocking sound is coming from underneath your car, that most likely means something has got loose or dislodged. Sensor issues can cause the air/fuel mixture to lean out. Check the lug nuts on the front wheels and make sure that they are tight. Bad Catalytic Converter. The issues can involve damaged suspension joints, brake rotors, loose calipers, carbon deposits, low oil pressure, etc. Engine knocking happens when there is a rattling noise from the engine bay when accelerating. If it makes knocking noise when accelerating, it could be your engine is worn out with low oil pressure or piston slap. You can’t ignore it, though, because it could be much more serious. If your car is making louder noises and you’re not sure where they’re coming from, you could be dealing with an engine knock, often referred to as pre-detonation or pre-ignition. If the lug nuts are tight, then check around the wheel and see if there is anything that could be making the wheel come in contact with it. Jun 24, 2022 · When accelerating or slowing down, a clunking noise from the front of your car can indicate weak motor or transmission mounts, a failing drive shaft, a failing shift solenoid, or a low transmission fluid level. If you hear a clicking noise while accelerating your car, worn or broken axles are likely the cause. Disabling the cylinder closest to the problem bearing journal should quiet the noise and help you to locate which one is at fault. It can also be detected under hard acceleration. This can result in a loud, knocking sound that can be heard from inside the vehicle. #52 · Jan 15, 2021. My guess with the right turning its a CV joint. Car makes noise when accelerating at low speeds, and slapping noise is one of them. Without a bushing, two or more metal components are rubbing together, making a knocking sound. Jan 23, 2022 · Let’s find out what parts can cause these sounds when accelerating. When there is a low proportion of fuel in this mixture, the result is multiple detonations and a loud knocking engine noise. 7 Fuel Injector Woes: Malfunctioning Injectors Create Noise May 22, 2022 · Knocking when Accelerating. Worn motor mounts. 4. Bearings, which let the cam and crankshaft spin, can also be noisy when they start to fail. Weld the loose mount and attach the exhaust pipe. Poor tires. That clicking sound you hear when turning is what you get when a CV joint gets dirt in it from a tear in the rubber boot. Look for a lot of grease around the rubber boot areas. Lug nuts: Loose lug nuts can also cause a clunking noise during acceleration. ”) You might have carbon build-up in the combustion chamber. Step 6: Inserting the new spark plugs. If your spark plugs are worn out, they should be replaced every 30,000 miles or so. You can clean the injectors yourself using some simple tools and fuel injector cleaner. Here is a link to a video of the knocking noise (links to a Google Drive video). Table Of Contents. The most common reason for slapping noise in your car is the defective transmission. A worn-out CV joint needs replacing immediately, so contact the garage right away. You should get this checked as soon as possible. The rubber portion of the coupling deteriorates over time; more rapidly if hard acceleration The sound can be best described as a metallic clunking, a 'tac tac tac tac' that the car makes when I am accelerating. There can be several reasons why you hear noise when taking your foot off the gas pedal: Loose heat shield: The heat shield that covers the exhaust system can sometimes become loose, causing a rattling noise when the car is in motion. 2. Overly advanced ignition timing can cause engine knock. #5 · Dec 9, 2014. Also, once rpms go over 2000, noise goes away. Goes away when you use premium fuel. [First time posting] We just got the 2018 Q5 a week ago and noticed a quirk. High octane fuels burn more uniformly and resist knock. Sep 2, 2009 · I am hearing a clunking/knocking noise when I accelerate and decelerate, especially in lower gears. the sound is only present when starting a car cold and driving and not when idle, and will disappear after the engine is warm, no noise if coasting and only on acceleration. Check the tyre pressure is correct or if you have a slow puncture. Step 4. Listen for squeaking or whining as you turn your car on and as you accelerate. A deep knocking noise can be an indication of a May 6, 2020 · 3 posts · Joined 2020. This can be tracked back to lubrication also–placing more demand on the system. Loose Cargo In The Trunk Or Under Seats. I was thinking it's the tranny mount, not sure what else it could be. 5 Low Oil Levels Can Leave Your Car Making Knocking Noise; 1. com/blkgilThere are many rea Shop for New Auto Parts at 1AAuto. Either you filled your gas tank with the wrong gas type the last time you were at the gas station, or the gas station supplied you with bad fuel. You can also use your car manual to know Jul 4, 2022 · Cogen Man. I don't hear any sounds until I take it close to 50 mph and let off the gas pedal, in which case I will hear a knocking sound. The knocking sound is not just one knock or bang but multiple knocks and it does not happen under normal driving and stops when you take your foot off the Sep 29, 2020 · Summary. to/c/149/dB/sway-bar-link-bushingIs there a knocking noise happening under your car or truck more than just Jun 9, 2024 · Could the rattling under the car when going over bumps also be the cause of a knocking sound under car acceleration? It is possible. kx xa ze ht gp co lk pw ib wn