The Reasons for Clunking Noises in Your Lexus From Certified Mechanics in Lowellby Mechanics Direct August 20, 2021
There are several reasons you may be hearing clunking noises coming from your Lexus, from the engine to suspension issues. It can be hard to self-diagnose. Below we will discuss some possible causes and what to do should you find yourself in this situation.
Under Your Lexus’s Hood
When you start up your vehicle, if you notice a clunking sound, it could indicate either failure of the starter or transmission flex plate. The flexplate is a part of the transmission. It connects the crankshaft to the torque converter. It is circular in shape, steel, with small holes, and “teeth”. The flexplate is made up of two parts, the flex plate itself and a ring gear surrounding the outer edge. It is designed to flex to help with the balance and smooth running of the engine.
Common causes of flexplate damage:
- An out of balance engine
- An out-of-balance torque converter
- A bad starter drive, which causes the teeth to break off
- Broken teeth, which can occur when you first start your car or while the engine is running
- The bolts are not torqued to the correct specification
- Manufacture defect
- Low-quality parts
Reasons for Noises
If you hear a clunking noise, pull your car over to a safe spot. If the noise continues, it is likely coming from the engine. Your Lexus is equipped with an internal combustion engine. This is a heat engine, meaning combustion of a fuel occurs with an oxidizer in a combustion chamber. This is a key part of the fluid flow circuit.
- Low engine oil: An illuminated warning light will be seen on the dashboard. A knocking sound from under the hood can be heard if there is friction between parts that need lubrication from oil. You may also smell burning oil. The engine will begin to overheat if your car is low on oil or if oil is leaking, since oil helps to pull out excess engine heat.
- Broken serpentine belt: The serpentine belt drives the alternator, power steering pump, water pump, air conditioning compressor, air pump, and more. With a broken serpentine belt, it may whip around inside the engine compartment, creating an extremely loud noise. You will not be able to drive your Lexus and it will need to be towed to a repair shop. The engine will also overheat immediately due to a non functioning water pump.
A clunking sound coming from your suspension system indicates that something is either loose or worn out. The suspension system of your Lexus is full of integral parts that must maintain proper working conditions to keep your vehicle on the road. Below are a few malfunctioning parts that may cause a clunking sound.
- Bad sway bar link: A sway bar link reduces the risk of a vehicle rolling over while turning. You may hear a knocking or clunking sound when you go over bumps and your vehicle will be difficult to handle if this bar is broken.
- Bad tie rods: Tie rods connect the vehicle’s steering rack to the steering arm. It is key in turning the steering wheel in the direction of the tires. When the tie rods are worn out, you will hear a clunking noise and the steering will feel significantly looser.
- Bad ball joints: Ball joints connect the wheel hubs of your vehicle to the suspension system components. When the ball joints are going bad, you will notice a clunking noise from the front tires and vibrations in the steering wheel.
Mechanics Direct for Your Lexus
Should you find yourself with a clunking noise coming from your Lexus, seek out our professional mechanics to inspect and diagnose the problem. At Mechanics Direct, we are here for you.
Our auto shop is in Lowell, MA and we service vehicles from surrounding cities including North Chelmsford, Dracut, Tyngsborough, and Westford, MA. Owner and operator, Mitchell Smith, has decades of service under his belt. In 1996, he implemented a direct line of communication between the vehicle’s owner and mechanic which has proven successful in customer satisfaction.
We service several vehicles including Acura, BMW, Honda, Lexus, Mercedes-benz, Subaru, and Toyota. Our mechanics specialize in check engine/warning light, suspension, transmission, and much more. Do not wait until a small problem turns into a huge issue. Give us a call today to schedule an appointment.
* Lexus Car image credit goes to: Alexander Shapovalov.