* Torque Converter: This is the most common cause. The torque converter acts as a fluid coupling between the engine and the transmission. If it's failing (worn clutches, internal damage), it won't effectively transfer the engine's power to the transmission. This often manifests as engine revving without acceleration.
* Transmission Problems: Several internal transmission problems can cause this. These include:
* Low or burnt transmission fluid: Low fluid leads to insufficient lubrication and can cause damage. Burnt fluid indicates existing damage and overheating.
* Worn clutches or bands: These components are responsible for engaging different gears. Wear or failure results in slipping and lack of power transfer.
* Faulty solenoids or valve body: These control the flow of transmission fluid, and malfunctioning components can prevent proper gear shifting.
* Broken planetary gears: These are internal gears within the transmission. Failure leads to significant power loss or complete lack of movement.
* Broken or faulty driveshaft: The driveshaft connects the transmission to the wheels. If it's broken or disconnected, power won't reach the wheels.
* Differential Problems: The differential allows the wheels to rotate at different speeds during turns. A problem in the differential can prevent power from reaching the wheels, even if the transmission is working.
* Wheel Speed Sensor Issues (less likely but possible): While less common in producing this specific symptom, a faulty wheel speed sensor could interfere with the transmission's ability to shift correctly, potentially leading to the described behavior.
Troubleshooting Steps (in order of least to most invasive/expensive):
1. Check the Transmission Fluid: This is the easiest and cheapest first step. Check the fluid level and condition. Low or burnt fluid is a strong indicator of a problem.
2. Have the Transmission Diagnosed: A professional mechanic with a scan tool can check for trouble codes stored in the transmission's computer. This can pinpoint the issue more precisely.
3. Inspect the Driveshaft: A visual inspection can reveal if the driveshaft is visibly damaged or disconnected.
Important Note: Driving the car with a severely malfunctioning transmission can cause further damage. It's best to have it towed to a mechanic rather than attempting to drive it.
