If your engine starts rattling as you accelerate, that’s your cue to visit your trusted mechanic as soon as possible. Unusual noise from under the hood is often a sign that there’s something wrong with your car, which can range from minor issues to serious engine trouble.
A rattle noise in the engine refers to any unusual sounds from the engine whenever you accelerate. It can be a loud and persistent sound or a softer, sporadic noise that comes from under the hood.
Hearing a rattling noise while accelerating is never a good sign, which is why it’s important to diagnose the issue as soon as possible. Here are possible causes to consider:
When transmission fluid is dirty or insufficient, the transmission’s components won’t be properly lubricated. This can cause several parts to grind against each other, causing the transmission to overheat and produce a rattling noise.
When an engine mount wears out, which happens over time, it won’t be able to hold the engine as well as before. This can create a rattling sound when the engine shifts and hits other metal components under the hood.
When the torque converter’s bolts are loose, it can cause at rattling noise when the car is idling. The sound typically gets louder and more persistent when you put the transmission in gear.
Wheel bearings typically last 85,000 to 100,000 miles, but poor maintenance and contamination can cause them to wear faster. Note that damaged wheel bearings create grinding or grating noises that get louder as you speed up, but not typically a rattling noise.
When you accelerate, a bent v-belt pulley can wobble around, creating loud vibrations in the engine bay.
When was the last time you had your tires rotated? Unbalanced tires can create vibrations that sound like unusual rattling when accelerating. If your tires are still in good condition, you can get away with a simple tire rotation. However, if they’re mostly worn out, you’ll have to replace them with a new set.
A vehicle with a manual transmission has a heavy steel flywheel bolted at its center to the crankshaft, and it is this flywheel to which the clutch pressure plate (cover) is bolted.
The clutch disk is splined to the transmission input shaft and the disk is pinched between the cover and the flywheel surface to transfer engine power through the transmission when the clutch is applied (foot off the pedal).
When the clutch is released, the pressure plate lifts and stops driving the clutch disk and input shaft when the vehicle is stopped, in gear, and idling, and between shifts. Problems with the clutch can cause a rattling sound.
In an automatic transmission, the flexplate takes the place of the flywheel in a manual transmission. The reason it’s called a flex plate is that the torque converter expands slightly with fluid pressure when the throttle is applied, and the flex plate literally flexes.
This can cause the flex plate to crack right around the outside of the bolt circle that attaches the flex plate to the crankshaft. Sometimes the flex plate is called the flywheel because it may have the starter ring gear made onto it. In other cases, the starter ring gear may be part of the torque converter.
The exact solution will vary depending on the actual culprit behind the strange noise in your engine. However, here are some examples of how to fix engine rattle sounds:
Sometimes, you might be dealing with something as simple as trapped debris in the undercarriage. Check your vehicle’s undercarriage for things like stones or twigs that got stuck in the undercarriage. When debris gets stuck there, it can hit metal parts and create a rattling sound.
You’ll have to shell out some money and replace the faulty component behind the rattling sound in your engine. Getting new wheels or buying a new torque converter might be expensive, but it’s still better than letting the problem get worse.
If your vehicle is low on manual transmission fluid, you’ll have to top it off according to your manufacturer’s recommendations. If the transmission has a leak, get the leak fixed or you’ll wind up destroying the transmission.
An unusual rattling sound when accelerating is a warning sign you should never ignore. Your vehicle might run with seemingly no issues now, but it’s only a matter of time before things get worse.
These strange noises can be caused by all sorts of engine trouble, which can further damage your vehicle. As soon as you hear a rattling sound, avoid driving your car until you can bring it to a mechanic for a proper repair.
If you hear rattling noises coming from your engine, there’s a good chance a part or component has become inoperative and needs to be replaced. It’s always a bad idea to drive a vehicle with faulty engine components, so make sure to conduct necessary repairs as soon as possible.
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Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.