Symptoms Of A Bad Torque Converter – How To Diagnose It Right?

Symptoms Of A Bad Torque Converter – How To Diagnose It Right?

Are you starting to experience how the transmission starts to slip gears more often and the transmission of the car simply doesn’t feel right and you assume that these are one of the tell-tell symptoms of a bad torque converter? If that is the case, then you are at the right place because you are going to learn everything you need to know when it comes to these symptoms.

Having a problem with the transmission is something that nobody wants. Transmissions are expensive to repair and also to replace. So, whenever this starts happening to you, you better act quickly and save what can be saved before the transmission fails completely.

But sometimes the cause for the problems is not only the transmission but the torque converter. And what is really unfortunate when it comes to these two is the bad torque converter vs bad transmission symptoms are somewhat the same. It is rather difficult for the untrained eye to make a conclusion about which of these components have failed. But you shouldn’t worry because we are going to help you out.

First, we are going to learn what is a torque converter and the torque converter diagram. Then we will dive into understanding how a torque converter works and the symptoms of a bad torque converter. After that, we will learn how you can diagnose and sort out this problem on your car and how much it will cost you to do so. So, if you want to learn more, follow along.

What Is A Torque Converter?

Now before we dive into more complex topics and start to understand how a torque converter works and the symptoms of a bad torque converter, let’s cover some of the basics and learn more about this component in general. Having the basic knowledge will make you a better troubleshooter and you will understand how this component works overall and what can you expect from it.

Nevertheless, a torque converter is a component that is used on classic automatic transmissions. These transmissions are also known as torque converter automatics since they implement this component.

The vast number of transmissions out there are torque converters. But still, there is some portion of CVT and DCT transmissions. And even CVT has a torque converter in most cases. So, what is a torque converter in general?

Well, a torque converter is a device that sits between the transmission and the engine. This is a fluid coupling device that helps the car from stalling when it comes to a stop. In addition to this, the torque converter is multiplying the engine torque to increase the pulling power.

The torque converter has the transmission on one side and on the other side the flexplate that is located at the back of the engine.

Basically, the shaft of the transmission goes through the torque converter and is connected to the engine. More on how the torque converter functions are going to elaborate later on before we learn the symptoms of a bad torque converter, but first let’s learn more about the torque converter diagram.

Torque Converter Diagram

Now before we learn the symptoms of a bad torque converter let’s learn more about the torque converter diagram. Let’s understand more about what components this converter is composed of.

Knowing the components will help your diagnostics process a lot easier and you will be able to tell if you are having a bad torque converter or a bad automatic transmission. So, from what components is this torque converter consisted? Let’s explain.

The torque converter is an enclosed device in which there are components. This torque converter works with the help of hydraulic fluid and you will never see an electrical component inside it.

The first component that comes from the side of the engine is the impeller or torque converter pump. The impeller rotates as the engine rotates. This component has blades and it is basically doing all the hard work and acts as a centrifugal pump.

This impeller turns the fluid in an outward direction to the turbine. The turbine is another component that is connected to the input shaft of the transmission.

In between the impeller and the turbine, there is a stator/reactor. The stator is a component that goes in one way and this stator is locked when the engine is working above idle.

By doing this, this centrifugal force acts on the turbine and by doing so, it multiplies the torque and gives you that pulling power that your car has. Overall, this is a complex process to understand from the first try. This is why we will attach a video where you can see and understand the work of the torque converter. Understanding how it works will help you further understand the symptoms of a bad torque converter.

How Torque Converter Works?

What is important for you to torque converter when it comes to the proper work of the transmission is to understand its purpose. You don’t need to know the whole science of the impeller, stator, turbine, and clutches. You only need to know the two core goals of this component.

The first thing that this component does is to prevent your car from stalling at idle. This torque converter is simply the same as your clutch in a manual transmission. When the transmission is disengaged the torque converter will transfer this motion to the transmission and your car will not stall in the process.

The second thing to know is that this torque converter is a torque multiplier. As you probably know, torque is one of the most important aspects since engine torque moves you forward. And the transmission is a simple torque converting box that converts the rotational speed of the engine’s crankshaft into torque.

And the torque converter helps you get bigger torque by multiplying this force and improving the performance of the car in general. So, when it comes to its function, we can conclude that this is a really important device that is in charge of controlling the torque delivery to the wheels.

And when this converter is not working, you will start dealing with symptoms of a bad torque converter, and more about the symptoms we are going to elaborate next.

Bad Torque Converter Symptoms

Now let’s move to the most important section of this article and the are the symptoms of a bad torque converter.

As you probably are aware, whenever a component fails or it is close to failure, there will be symptoms that will be present around. This is why you should know every one of them.

Luckily for you, we are going to share them all with you, and on top of that, we are going to give our opinion on how probable they will be whenever there is a problem with the torque converter. So, if you want to learn more about this, follow along till the end.

1. Check Engine Light

The first symptom in our list of symptoms of a bad torque converter is the check engine light. Even though this component is not connected to the PCM directly, there are still some solenoids in the transmission that are regulating the work of the torque converter and whenever this component fails, you will get a check engine light concerning the transmission.

But you can never know if the torque converter is really bad unless this component is removed from the car and properly inspected.

Symptoms Of A Bad Torque Converter

Nevertheless, the most common codes that indicate problems with the torque converter are the codes ranging from P0740 to P0744. These codes are most critical because they indicate an issue with the solenoid for the torque converter clutch.

So, whenever you get one of these codes, you need to further investigate and see if the solenoid is faulty and if the solenoid is not faulty, then the problem lies in the converter and this component probably will require to be replaced. Now let’s continue with the other symptoms of a bad torque converter.

2. Bad Torque Converter Noise

The next symptom in our list of symptoms of a bad torque converter is the torque converter noise. Whenever this component starts to fail, it will start to produce different noises that will come from the transmission.

In the beginning, you might start thinking that this is caused by a bad transmission. But this isn’t always the case since this converter can also cause problems like these. So, what are the most common noises that develop from this component?

The most common sound that is associated with a bad torque converter is the whining noise. Whenever the torque converter starts to fail it will start developing these whining noises. These noises basically sound the same as when a power steering pump starts to fail. They are so similar because they both function similarly and use hydraulic fluid.

The whining sound is often caused by a failing clutch mechanism and when this clutch pack wears too much it is going to start rattling and it could cause the torque converter to fail completely. This is why you need to beware of these symptoms of a bad torque converter on your car. Now let’s move on to the next symptom.

3. Inconsistent Car Speed

Another in our list of symptoms of a bad torque converter is the inconsistent car speed. This is often caused by a bad torque converter clutch pack.

The torque converter simply will start to malfunction. Sometimes it will engage and sometimes it will disengage and this will affect the car’s speed.

The hydraulic pressure inside of the torque converter will not be up to the task and will vary non-stop. And when this happens, the car will be really difficult to drive since the car speed will not be stable.

Symptoms Of A Bad Torque Converter

You can accelerate too quickly or come to a stall. And this car is not safe to drive. You just don’t want to end up stranded in the middle of the road because of your transmission.

Whenever there are abrupt changes in speed that don’t reflect your pedal input, then you should address this problem and try to sort out the issue as soon as possible. Frankly, this is one of the tell-tell signs that you have a problem like this. Beware of these symptoms of a bad torque converter, now let’s move on to the next symptom.

4. Transmission Shudder

The next symptom in our list of symptoms of a bad torque converter is the transmission shudder. Whenever the clutches inside of the torque converter are not working well, you will experience a transmission shudder. But what is a shudder?

Well, a transmission shudder is when you start to experience vibrations from the transmission. This transmission shudder will be most notable when you get up to speed. Especially between 30 and 45 mph.

You will notice how there will be vibrations coming from the transmission, the console will shake and rattle and this shudder will really ruin your day.

At first glance, you might think that this could be a problem with the transmission itself. But this isn’t always the case. Even though the transmission can also shudder if the transmission fluid is dirty or low. But still, you need to take things further and diagnose the problem. And later on in the article, we are going to explain how this is done.

5. Transmission Overheating

The next symptom in our list of symptoms of a bad torque converter is the situation when your transmission starts to overheat.

This is often the case on these transmissions that have worn torque converters. There is a ton of debris from the clutches in the transmission fluid. And this fluid basically makes the transmission overheat and causes you trouble.

When this will be the case, the transmission could stop shifting, or the car to notify you to stop the vehicle in order to cool off.

Symptoms Of A Bad Torque Converter

What is most important in these situations is to check the transmission fluid and its condition. In most cases, low fluid or dirty fluid can cause the torque converter not to work well and overheat the transmission.

This is why the fluid should be the top priority for you to handle before the problem becomes bigger. Now let’s move on to the following symptoms of a bad torque converter.

6. Transmission Slipping Gears

The next symptom in our list of symptoms of a bad torque converter is the situation when the transmission is slipping gears.

When the torque converter fails, this is a fairly common issue. The torque converter is simply damaged on the inside and cannot handle the transmission fluid the right way.

It can either take too much or too little fluid into the automatic transmission. And when this happens this will make the transmission slip gears. But what is the situation when the transmission slip gears? Well, this situation can be simply explained as a failure of the transmission to stay in a certain gear and will drop a gear or two all of a sudden. This means that it slips gears.

So, whenever you notice something like this, it is your top priority to check the fluid level first and then if the fluid is good, then it means that this is either a problem with the internals of the transmission or a problem with the torque converter. Now let’s move on to the last in our list of symptoms of a bad torque converter.

7. Stalling Issues

And the last in our list of symptoms of a bad torque converter is the stalling issue. Whenever the torque converter has failed, it will either like to stall on startup or the engine RPMs will increase.

Transmission gearbox problems diagnose troubleshooting repair

In our case, is the stalling problem. So, whenever your car stalls at idle, it doesn’t mean that you have ignition problems. It could just be a bad torque converter that is not doing its job of keeping the engine afloat when the engine is idling.

But how can you really tell if a torque converter is good or not? Well, more on this we are going to elaborate on in the following chapter, where we are going to explain how this procedure is done in detail for you to have a better idea of what you can expect when performing tests on the torque converter.

Diagnosing A Bad Torque Converter

Now enough on the symptoms of a bad torque converter, let’s now move on to other topics. Namely, the diagnostics process of the torque converter. Let’s learn more about how this component is diagnosed properly and determine what you can do about it.

The first thing that you need to beware of is the symptoms as we mentioned. Whining noise coming from the transmission, shudder, engine stalling at idle, or check engine light. All these could be symptoms of a failing torque converter. And if you have one of them, especially the ones that directly are associated with this component then you need to diagnose the converter.

For example, when you get codes on the OBD2 scanner in the range between P0740 to P0744. All, these codes are closely associated with this component or the TCC solenoid. In these cases, both of these components have to be checked. If the solenoid is good, the torque converter is probably bad.

Also, you can bench test the torque converter as well. You can see in the video how this procedure is performed on a torque converter. The only thing you will need is an air compressor. But the tricky bit is the removal of this component which can be rather difficult. If you deemed that this component is bad, then you have to replace it. And more on this in the next chapter.

Torque Converter Replacement

Now as we cleared all symptoms of a bad torque converter, let’s now move on to other topics and learn more about the replacement of this component.

What is worth noting is that the replacement of this component is not beginner-friendly. For this job, you will definitely need a lift and also a pair of extra helping hands to help you bring down the transmission and replace this unit.

This is why we would recommend replacing it at a shop. How the procedure is done, you can check in the video.

Torque Converter Replacement Cost

The cost to replace this torque converter is not cheap. You can expect to pay a good amount of money to replace this component. But how much to be more exact?

For the whole job, you can expect to pay somewhere in the range of $600 and $1,200. Which is not cheap, but still, it is quite necessary to do if you want to resume driving.

Torque Converter Troubles: 6 Signs Your Automatic Transmission Needs Attention

  1. A failing torque converter is one of the most common transmission problems that can lead to other internal transmission damage.
  2. Loss of acceleration, physical shuddering when stepping on the gas pedal, and sluggishness are signs of a possible torque converter issue.
  3. Slipping between gears or difficulty staying in a certain gear can indicate a torque converter problem.
  4. If the vehicle won’t shift into a specific gear or the transmission is overheating, it may be due to a failing torque converter or other internal damage.
  5. Transmission fluid leaks are a common source of the torque converter and transmission problems and should be addressed immediately to avoid major internal damage.
  6. Dark, burnt, milky, or debris-filled transmission fluid (for more insight, check out our guide on milky transmission fluid) may be a sign of internal transmission or torque converter problems that require expert inspection and servicing.


In this article, we have covered quite a bit when it comes to torque converters. First, we learned what this component is and how it works.

Then we covered the symptoms of a bad torque converter and we learned how you can diagnose a bad torque converter. Lastly, we covered the diagnosis, replacement, and cost involved in this job.


Now let’s answer some frequently asked questions.

What Is A Torque Converter

A torque converter is a special device that is installed between the transmission and the engine. This is a coupling device that bonds these two components together and helps the transmission work better.

What Does A Torque Converter Do

A torque converter has the goal to prevent the vehicle from stalling when the car comes to a stop. This device also is multiplying the engine torque when the car is accelerating in order to increase the pulling power of the car.

What Are The Symptoms Of A Bad Torque Converter

Some of the symptoms of a bad torque converter might include the transmission slipping gears, shuddering, check engine light, dirty transmission fluid, and noises coming from the transmission. Overall, these are the main symptoms that should trigger you when dealing with this component.

What Causes A Torque Converter To Fail

In most cases, the dirty transmission fluid damages the torque converter. This fluid is creating a ton of friction inside of the component and the clutches and needle bearings will fail prematurely. Whenever this is the case, the converter either has to be rebuilt or replaced. If not, it will damage the transmission.

Where Is The Torque Converter Clutch Solenoid Located

The TCC solenoid is located inside the transmissions. More precisely behind the transmission oil cover. You just need to remove the cover and filter, drain the fluid and you will be able to reach the TCC solenoid. For the exact location consult with a repair manual for your specific transmission.

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