Your vehicle is a complex piece of machinery. The engine in particular can make a bevy of noises as it sucks, compresses, and ignites the air-fuel mixture in the cylinder. The same can be said for the automatic transmission and suspension. But one of the most common complaints on older cars is a rattling noise when accelerating.
Rattling noises can either be a simple fix or an impending sign of a serious problem. In all honesty, it can be tricky to diagnose such a problem unless you bring the car to a certified mechanic.
But there are things you can check under the hood to find that annoying rattling noise as you accelerate the vehicle. In some cases, the rattling noise might be caused by something mundane such as a loose heat shield in the exhaust manifold, or some other damage to the manifold. Just a few months ago I found and annoying clunk on my Dodge Ram that was caused from the plastic wheel well bouncing against the frame because it wasn’t fully secured!
How to Find Rattling Noises in the Car
The first step you need to take is to isolate the cause of the rattling noise. Does it occur only when accelerating the vehicle? Or is the noise prevalent even during idling or cruising? Is the rattling noise coming from the front or rear? By determining the source of the rattling sound, it will be easier to diagnose the fault.
Take a friend with you as you drive, preferably someone who knows a thing or two about cars. Open all the windows and turn off the radio. Find a nice and quiet place to drive to make the job easier. Step on the gas and accelerate slowly and wait for the rattling noise to occur.
Possible Causes of Engine Rattling Noises When Accelerating
If you have an older car with a lot of miles on the odometer, rattling noises in the engine can be caused by the following problems:
1. Issues with the valve train
Do you hear rattling noises similar to the sound of clinking bottles when accelerating the vehicle? The noise is caused by a sticky valve train. Some experts even call this rattling noise as ‘carbon rap’ and is caused by worn or sticking valves and hydraulic lifters. Carbon rap is caused by premature ignition of the air and fuel mixture inside the motor. It can also be caused by dirty oil and using the improper fuel octane required for your vehicle.
2. Transmission problems
This solution is ideal for vehicles equipped with automatic transmissions. Similar to the engine, the A/T will only run properly when filled with the right amount of transmission fluid. Rattling noises when accelerating can be caused by low fluid levels in the A/T. Open the hood and check the fluid level. If the car is running low on transmission fluid, refill the reservoir to the proper level. After doing this, start the car and take a short test drive to see if the problem goes away.
3. Worn out belt pulleys
Worn out or broken belt pulleys might be the culprits if there is a constant rattling sound as you accelerate the vehicle. The pulleys will spin faster as the engine speed increases. Damaged pulleys will also cause engine noises even at idling speed!
If you have more questions about why your car is rattling, give us a call at Callahan Automotive to have your vehicle inspected by our mechanics today