Torque Converter Noise in Park and Neutral - Serious Problem?

If your torque converter makes a noise while in park and neutral, it indicates a problem. Some common culprits are damaged or worn-out torque converter clutch, faulty stator bearing, low transmission fluid levels, or the use of poor-quality fluid.

Torque converter noise problem highlights

• Level of importance:High
• Reasons:Torque converter problem, actually loose bolts
• Needed expertise:High
• Needed tools:Basic tools
• Time taken:1.5-3 hours
• Can you drive? Not recommended
• Possible issues: Torque converter damage, fatal transmission damage.

Understanding Torque Converters

If you've driven a manual car, you are familiar with the process of pressing down on the clutch before changing gears. In automatic cars, you don't have a clutch, instead, you've got the torque converter. Torque converters consist of hydraulic devices that allow it to amplify and transmit power from the engine to the transmission and seamlessly switch between gears. To comprehend the severity of torque converter noise in park and neutral, you first need to understand the basic functioning of the torque converter.  

How Does It Work?

The torque converter consists of 3 main components, the impeller, the turbine, and the stator. The impeller is directly connected to the engine and is tasked with driving the transmission fluid. As the engine spins, so does the impeller allowing the transmission fluid to flow. 

The flow of transmission fluid reaches the turbine and starts spinning the turbine. The turbine is connected to the input shaft of the transmission. 

The stator is positioned between the impeller and the turbine and plays another huge role. This part is the reason why it is called a torque converter as it alters the direction of fluid flow. It receives the fluid from the turbine and forcefully pumps it towards the impeller. 

What Does A Torque Converter Do?

Your engine should be running at all times when your car is operating. This is easy to comprehend when you are driving as the power from the engine is transferred to the drivetrain and the wheels. But what about when you are in a traffic jam and your car isn't moving? Your engine doesn't shut down and the crankshaft continues to spin but your car doesn't move. 

This is where your torque converter comes in. Your engine and transmission are two different components. And the torque converter is what connects the two. When your car is stationary, the torque converter simply stops connecting the two, which allows the crankshaft to keep spinning without transferring the power to the transmission.

The torque converter also plays a vital role when accelerating as it multiplies the torque produced by the engine at low RPMs. This creates enough power for acceleration. 

Causes Of Torque Converter Noise

Now that you know what happens inside your torque converter as it goes into neutral or park, you can better understand what causes the torque converter noise. Here are a few common causes for torque converter noise in neutral and park. 

1) Damaged Torque Converter Clutch

The torque converter clutch is tasked with engaging and disengaging the transmission's input and output shafts. A worn or damaged torque converter clutch will not be able to fully engage and this could end up causing noises when switching gears, or when you put your car in park or neutral. 

2) Faulty Stator Bearing

You already know what the stator is and its function. The stator bearing is what supports the stator within the torque converter. Just like any other bearing on your car, the stator bearing is also prone to wear. If your stator bearing is worn or damaged, it could lead to noises when it spins. 

3) Worn Stator

The stator is the heart of the torque converter. So it's not hard to imagine that your torque converter will fail and start making noises in park and neutral when your stator has worn off. With the constant flow of fluid, the stator can wear off. Usually, the stator tends to last around 5 to 10 years, but it mainly depends on riding conditions and maintenance. With proper maintenance, your stator can easily outlast your car. 

4) Low Transmission Fluid

More often than not, when your torque converter is making a noise in park and neutral, the problem is associated with the transmission fluid. Transmission fluid is the lifeblood of the system, as it acts as a hydraulic fluid, keeps the temperature at optimal levels, works as a lubricant, and helps keep the system clean. 

Without enough transmission fluid, the metal components in your torque converter will not have adequate lubrication. Since, they constantly grind against each other, without lubrication, you will start hearing noises from your torque converter in park and neutral. 

Apart from the torque converter noises in park and neutral, you'll also start to face a plethora of other problems if you are running low on transmission fluid. 

5) Dirty Or Poor-Quality Transmission Fluid

There is a reason why manufacturers recommend you replace your transmission fluid every now and then. This varies from car to car, but you should always heed your manufacturer's advice and replace your transmission fluid as recommended. 

With time, your transmission fluid becomes dirty and loses most of its lubricative properties. So, this will also increase the friction and result in accelerated wear as well as weird torque converter noises in park and neutral. 

Implication Of Torque Converter Noise

If you are here, you are probably wondering how serious this problem really is. Do you really need to be worried when your torque converter is making noises in park and neutral? 

Torque converter noises in park and neutral should not be ignored as they can directly affect your transmission. You don't need to be a gearhead to understand that your car cannot be driven without a functioning transmission. The sooner you resolve the problem the less likely you are to suffer major transmission damage.

But, what exactly will happen if you ignore the problem?

1) Increased Wear

Whether your torque converter noise is caused by a lack of transmission fluid or damaged components, it will lead to increased wear on your torque converter and transmission. Excessive wear can lead to reduced performance, decreased efficiency, and ultimately, the failure of the torque converter or transmission.

2) Transmission Damage

When your torque converter is failing, it will directly reflect on your transmission. Continued operation with a malfunctioning torque converter can place additional stress on the transmission system, causing damage to other components such as gears, bearings, and seals. So, ignoring torque converter noise in park and neutral and failing to make the necessary repairs can end up costing you thousands of dollars. 

3) Reduced Fuel Efficiency

You are probably wondering what's the relationship between the torque converter and fuel efficiency. For example, if your torque converter clutch is worn or damaged, it will fail to properly engage and disengage. This will cause your gears to slip resulting in power loss and reduced fuel economy. A faulty torque converter will also fail to build enough pressure to transfer torque properly, which again will result in slipping gears. 

4) Transmission Overheating

If the torque converter noise in park and neutral is caused by anything transmission fluid-related, chances are that your transmission is also overheating. Insufficient fluid or degraded fluid will lead to increased friction and heat. When your transmission overheats, it'll surely lead to further damage to internal components. 

5) Breakdown

This is inevitable if you continue to ignore torque converter noises in park and neutral. Eventually, the noises will lead to the total failure of your torque converter or your transmission. If either of those fails, your car will be rendered undrivable. 

How To Solve Torque Converter Noises In Park And Neutral?

As mentioned, more often than not, whenever you hear torque converter noises in park and neutral, it is related to your transmission fluid. So the best way to tackle the problem is by flushing and replacing your transmission fluid. This is a simple and cheap procedure that you can do by yourself with some basic tools. Hopefully, this solves the torque converter noises in park and neutral.

If it doesn't then it is best if you take your car to a professional. A proper diagnosis will allow you to know whether your torque converter is salvageable. The torque converter is not a cheap part to replace. But with a diagnosis, you might be able to limit the damage by replacing the stator bearing, stator, torque converter clutch, or any other component of the torque converter without replacing the entire unit. 

Conclusion

There is no denying that the torque converter is a vital part to keep your car operational. Under normal circumstances, it should not make any noise. If you hear torque converter noise in park and neutral, you should immediately work on finding a solution. 

The best way to protect your torque converter is with regular maintenance. Adhere to your manufacturer's recommendations, and replace your transmission fluid at the right interval. Also, make sure to use the right type of transmission fluid for your vehicle.