Torque converters are associated with automatic transmissions—more like they are partners in motivating your car to go. When you have transmission-related troubles, most assume it must be the transmission causing all the problems.
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It could be the torque converter that’s the issue, so we’ll cover the most common problems with them and how to fix each issue.
#1 – Your Transmission Is Slipping
When you shift into drive and step on the gas pedal, you expect your car to go forward. Sometimes that doesn’t happen, and it just revs the engine with little to no movement.
When that happens, your transmission is probably slipping due to the torque converter not building pressure inside.
How to Fix It
The torque converter uses transmission fluid to build pressure between a turbine-like unit inside the housing. If the transmission fluid is low, it can cause pressure to not build correctly.
- The first thing to check is if the transmission has fluid inside by pulling the fluid-level dipstick.
- If the car has not been running and the fluid is cold, you should see fluid on the dipstick.
- If the car is warm, you can check the fluid level against the full mark on the dipstick.
- If the fluid appears to be low, you should add fluid to the transmission dipstick tube until the fluid level meets the full mark on the dipstick.
Once you add fluid, the torque converter should build pressure correctly.
If the fluid level is full, and the torque converter is slipping, it may need to be replaced. This is a difficult job that requires removing the transmission. It may be best to take it to a specialized mechanic for transmissions to ensure a proper diagnosis and then to replace the torque converter if it has gone bad.
#2 – Your Car Has A Rough Idle
The torque converter builds consistent pressure and should not affect the idle characteristics of your car.
If you feel that the idle of your engine is lower or higher than expected, it may be because the torque converter is building pressure differently than it was designed to do.
How to Fix It
The torque converter can be removed and checked for proper pressure during use, but it is going to require removing the transmission and finding a company that can properly check the converter.
Be sure to have the car checked for vacuum leaks or other potential problems that can affect the idle of your engine before working on the torque converter.
#3 – Your Car Has Feels Rough During Acceleration
The acceleration in your car should be smooth. If you feel the car accelerate and then start to slow down briefly, it may be from a defective torque converter that doesn’t build proper pressure.
You can also check the tachometer in your car to visually see how the car accelerates. If the tachometer jumps up and down with the engine RPM, it can indicate the torque converter is the problem.
How to Fix It
Before you assume the torque converter has a problem, let’s check the simple items first.
- Ensure the transmission has the proper amount of fluid. You can pull the transmission dipstick out and verify if the fluid is at the correct level.
- You can also use a scan tool that will check the vehicle for diagnostic trouble codes. Most newer cars will set a trouble code relating to the transmission if it detects a problem such as rough acceleration.
If there are no trouble codes and the fluid appears to be full, it may be time to take the car to a qualified mechanic who can diagnose the problem further.
If the torque converter is the problem, the transmission must be removed to replace the converter.
#4 – Your Car Won’t Move When In Gear
The torque converter uses the power from the engine to build pressure inside the turbine of the converter housing and then transmits that power to the transmission.
If the car won’t move when the transmission is put into any gear, the torque converter could be faulty and not build the correct pressure.
How to Fix It
There are many reasons that can cause the transmission to quit working when placed into any gear.
You want to ensure the transmission is full of transmission fluid.
- If the fluid is full, check the color of the fluid. It should be a red or a red(ish) color, but as it ages it will change to an orange color.
- If the fluid is orange or brown, it indicates the fluid needs to be replaced as well as the transmission fluid filter.
- The fluid should also be clean.
- If there are any shiny metal flakes in the fluid. It indicates a problem with the transmission and not the torque converter.
You can also use a scan tool once again. If there are no trouble codes and the transmission is full of clean fluid, you need to book your car in with a qualified mechanic that can diagnose the problem further.
If the torque converter is the problem, unfortunately, the transmission must be removed to replace the converter.
#5 – Your Transmission Is Overheating
The transmission uses fluid for cooling and lubrication, but heat is the transmission’s arch nemesis.
Heat will break down the transmission fluid and prevent proper lubrication and cooling of the transmission parts.
A slipping torque converter can cause the transmission fluid to overheat to the point of boiling. When that happens, the transmission may be damaged significantly.
How to Fix It
Most newer cars have sensors in the transmission system that detect significant heat building in the transmission fluid before there is a problem.
If your car registers a diagnostic trouble code, be sure to have it checked.
Low fluid levels can cause heat buildup in the transmission fluid, and so can a blockage in the transmission cooler near the radiator or front of the car. If the fluid is full and is a red color, it may be time to take the car to a qualified mechanic for further diagnosis and repair.
#6 – You Hear Noises Coming From The Transmission
The torque converter is located between the engine and transmission. If you hear noise such as banging or rattling coming from that area, it could indicate a problem with the torque converter.
The torque converter has moving pieces such as bearings that can go bad without any other symptoms. The torque converter can still function properly, but it will make more noise than previously noted.
How to Fix It
If the torque converter is making significant noise, it indicates that something has been damaged or has failed. Internal bearings in the torque converter can fail and will shed metal flakes into the transmission fluid.
You can verify the transmission fluid level and condition (both color and contaminants) to understand what is happening inside the torque converter and transmission.
If the color of the transmission fluid is anything other than red, or if the fluid has contaminants trapped in the fluid, you should take the car to a specialized mechanic who can diagnose the problem.
Noise in the torque converter or transmission can indicate a larger problem that needs to be repaired.
#7 – You Find A Leak Under Your Car
One of the most common issues with torque converters and transmissions is fluid leaks. The torque converter has seals that prevent the fluid from leaking out of the housing, which can contribute to low fluid levels, slipping, and rough acceleration.
If you find a pool of fluid underneath your car around the engine and transmission area, the torque converter seals may be leaking fluid.
How to Fix It
Leaking seals can be replaced, but it requires the torque converter to be removed from the car.
It’s a significant amount of work that you can do at home with the right tools. It may be easier to take it to a mechanic who has the proper tools and equipment to remove the transmission and replace the seals.
Also, change the transmission fluid and filter at the same to prevent future issues caused by old fluid.

