There is a rattling when accelerating only in my 2012 Mitsubishi Lancer

There is arattling noise only when accwlerating what could it be

My car has 65892 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hi there. This is typically caused by a loose exhaust heat shield. Over time these will come loose and cause this to occur. In most cases the heat shiled can be welded to keep it from making noise. In other cases this is caused by exhaust noise due to worn out engine mounts. Those should be fully inspected also. If you are going to have this repaired, consider YourMechanic, as a certified mechanic can come to you to [diagnose where this rattle is coming from] https://www.yourmechanic.com/services/loud-squealing-or-rattling-is-coming-from-engine-inspection

How to Identify and Fix Common car Problems ?

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The most common reasons a Mitsubishi Lancer has a rattling noise are the ball joints, struts or strut mount, or a problem with the sway bar links.
You usually hear this noise when accelerating the vehicle. Most people call this a pinging or rattling sound. This noise is caused by an air/fuel mixture in the engine cylinder being ignited prematurely by the heat of compression as the piston is moving up on the compression stroke.
This is usually an issue with the rear suspension, which gets load placed on it when you accelerate. If the suspension isn`t working properly, it can allow the axle or other suspension components to hit the tailpipe, particularly where it goes over the axle.
This rattling noise should not be taken lightly as it warns of upcoming timing chain failure. The cause of the noise is faulty timing chain guide rails and timing chain tensioners that wear out well ahead of schedule. These components are there to keep the timing chain tight and properly positioned.
Rattling Noise – Once your catalytic converter becomes older or damaged from fuel mixtures, the honeycombs on the inside can begin to collapse and/or break apart which will cause a rattle to occur.
Sometimes the rattling sound during acceleration is caused by a loose bracket on the exhaust system or another mechanical component. The issue could also be a small exhaust manifold leak or something entirely different.
A loose center console cover, broken glove box hinge, or even an item resting in the door panel pocket or cup holder can suddenly start rattling at idle. So, if you hear rattling when your car is idling, check carefully around the interior, including the trunk or cargo area.
A loud squeaking or squealing noise while accelerating could mean there`s a problem with your engine belt. It could mean the belt`s loose or worn. Or it could mean that one of the belt`s pulleys is starting to fail. A loud rumbling noise when accelerating might suggest there`s a problem with your exhaust system.
It`s not usually a good idea to drive a long time after you discover the engine making noise for this reason. It`s going to cost around $500 to $1,500 to replace the timing chain or timing belt tensioner. Left alone, the timing belt could skip or break, causing your engine to not run due to engine failure.
When you let off of the gas pedal, the engine acts as a brake, so it wants to tilt in the opposite direction as when you are pressing the gas pedal. If there is excessive wear in the mounts, this will give it room to move/rattle/vibrate.
Rattling noises that appear when you`re driving over bumps, or on uneven surfaces, are often down to the suspension. These rattles can disappear once you speed up a bit or when the going gets smoother. The culprits may be the drop links (e.g. if they`ve snapped), worn bushes or corroded shock absorbers.
If your car is rattling, it could be an issue with the drive belt, catalytic converter, exhaust system, or another problem, depending on where the rattling is located. Rattling is a common symptom of a car part that has come loose, broken, or disintegrated.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Have a Mitsubishi Lancer 30th anniversary 2011, making a rattling noise when accelerating and loss of power. There is occasional smoke.
ANSWER : Hi there. The rattling noise is the ignition system being too retard or advanced as the engine is accelerated. Check the camshaft position sensor and see if the sensor is connected and sending a voltage reference to the computer. To check this, put a paper clip on the wires coming out of the harness plug (known as back probing) and check to see if there is power as the engine is running. If there is no power or if the power is weak, then I recommend replacing the camshaft position sensor. If the sensor is working, then I recommend replacing the spark plugs with the OEM specified spark plugs. If you need further assistance with diagnosing your engine noise, then seek out a professional, such as one from Your Mechanic, to help you.

A tin metal like rattling sound when I accelerate from a low speed.
ANSWER : Hello. My first inclination would be to say, "torque converter". That is easy to rule in or out as you might be able to get a "free" diagnosis from a transmission shop. I’m not recommending you repair it there but it is not unreasonable to seek advice. The reason for my first inclination is you mention a degradation in acceleration. If the torque converter has an internal fault you could experience poor acceleration along with noise. To rule out obvious simple causes, check the fluid level in the transmission per the instructions in the owner’s manual (follow carefully; otherwise reading will be meaningless). Whether it is the torque converter or another cause (front wheel drive, or engine related for instance), YourMechanic could give you a definitive diagnosis of the rattling sound, after an inspection, and indicate your repair options. Good luck with this.

Can I make my 2010 Mitsubishi Lancer auto lock when putting it into D and unlock in R. 2010 Mitsubishi Lancer
ANSWER : Hi there. Unfortunately this vehicle will only work with the doors locking when putting the vehicle into drive and unlocking in park. There is no way for this to happen when putting the vehicle into drive. It can possibly be done with some rewiring of the circuits, but I would not recommend this as it would cause other issues.

Front end rattling noise in 2005 Mitsubishi Lancer ES
ANSWER : When you get rattling, there are so many possible causes for the rattle. Watch my older video “finding the source of car noises.” I’ve got this cool device that you can get on eBay, used for 50- 80 bucks. It has a receiver and four transmitter units.

What it does is clamp it on different areas and when you drive, you wear headphones, and you push the numbers, and when you get the noise alarm you know where the noise is coming from.

That’s what I advise you to do because you’ve changed most of the major parts, but there are still other things like transmission mounts and motor mounts.

You’ve said that you set the strut mounts, but there are bolt joints, and all kind of things there that can make noise. If you jack it up and pull it in the tires and you cannot feel anything wearing, then you’d want someone with one of those machines like I have to go through and actually listen while he drives down the road to pinpoint exactly where the noise is coming from. If you need help with this, a technician from YourMechanic can come to your home office to diagnose your car’s rattling noise.

Just bought a used Forester that started rattling when I’m not accelerating and the wheel is straight. Any ideas on what it could be?
ANSWER : Hey there. The most common source of rattles on Subaru’s are the exhaust heat shields. They can rattle under all sorts of random circumstances. Whenever you turn, accelerate, let off the gas or brake, the motor experiences torque that is dampened by the engine mounts so the passengers won’t feel these vibrations. This torquing will affect the exhaust as much as any other component on the car. Checking for exhaust shield rattles is fairly simple. Use a soft mallet hammer to tap on the shields to see if it rattles. If it does, repairing this is more challenging than locating it. It’s a creative process that can only be decided in person. Of course, you will need to get under that car to access all of the shields.

Other than the exhaust shields, it could be a dust shield on the brakes or a sway bar end link. Both of these are far less common as determined by your description of your symptoms. If it is a sway bar end link, it will rattle most often when you go over bumps. If it is the brake dust shield, you will need to remove the wheel to see if the shield is loose.

If you need further help having this done, a certified professional from YourMechanic can come to your car’s location to diagnose the rattling noise so that this can be corrected.

There is a rattling when accelerating only in my 2012 Mitsubishi Lancer
ANSWER : Hi there. This is typically caused by a loose exhaust heat shield. Over time these will come loose and cause this to occur. In most cases the heat shiled can be welded to keep it from making noise. In other cases this is caused by exhaust noise due to worn out engine mounts. Those should be fully inspected also. If you are going to have this repaired, consider YourMechanic, as a certified mechanic can come to you to [diagnose where this rattle is coming from] https://www.yourmechanic.com/services/loud-squealing-or-rattling-is-coming-from-engine-inspection

I have a 2012 equinox and it is rattling upon acceleration and kind of rough idleing when stopped
ANSWER : In practice, oil consumption varies quite a bit, so much so that there is no agreement on what is excessive. As a "general" rule though, if an engine uses a quart of oil or more in 1,500 miles, that’s excessive. If you believe your engine’s oil consumption is too high and want the cause identified by a certified Mechanic, dispatched by YourMechanic right to your location, please request an oil leak/consumption diagnostic and the responding certified mechanic will identify the root cause of the problem for you. Obviously, you could have internal or external leaks, or both.

The causes of rattling on acceleration are varied but in your circumstance could be pinned down in a vehicle noise diagnostic. Causes include motor mount defects, loose parts and faults in components driven by the serpentine belt. There are many other causes though.

Common causes of rough idling include uneven cylinder compression, vacuum leaks, an air induction fault such as a stuck idle air control valve or a faulty throttle position sensor, problems with the mass air flow sensor, defective spark plugs, a weak coil and defective oxygen sensor(s). If you desire that this problem be diagnosed by a certified Mechanic, please request a rough idle diagnostic and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

How do I remove windshield reservoir on my 2012 Mitsubishi Lancer.
ANSWER : Hi there. There are 3 bolts that secure the windshield washer reservoir on the car. There is one bolt on the inner fender and the others are on the outer fender. A small socket and wrench set will remove the system. If you need further assistance with your windshield washer reservoir, then seek out a professional, such as one from Your Mechanic, to help you.