* Torque Converter Issues: The torque converter is the fluid coupling between the engine and transmission. If it's failing, it might not be able to handle the load when you put the car in gear, causing the engine to stall. This is a common problem in older vehicles.
* Transmission Problems: A failing transmission (internal problems, low fluid, worn clutches) can prevent it from engaging properly. The engine might not have the power to overcome the resistance.
* Low Transmission Fluid: Critically low transmission fluid will lead to overheating and damage, often resulting in the car stalling when put into gear. Check the fluid level and condition (color, smell).
* Clutch Issues (if it's a manual transmission): Although less likely on a Century of this year (which is almost certainly an automatic), if it *were* a manual, a worn clutch or problems with the hydraulic system would cause stalling upon engagement.
* Engine Problems: While less likely to cause stalling *only* when shifting, a weak engine (due to worn parts, poor fuel delivery, or ignition issues) might struggle to overcome the load presented by the transmission when you put it in gear. This would likely be accompanied by other symptoms, such as rough running or hard starting.
* Shift Linkage/Cable Problems (Automatic): Less common, but a problem with the linkage or cable that connects the gear selector to the transmission could prevent it from engaging correctly.
* Neutral Safety Switch: This switch prevents the car from starting unless it's in Park or Neutral. A faulty switch might not be correctly sensing the gear position, leading to stalling when engaging a gear.
Troubleshooting Steps:
1. Check Transmission Fluid: This is the most important first step. Low or dirty fluid is a common cause.
2. Listen for Unusual Noises: Any grinding, whining, or banging noises from the transmission area point to internal problems.
3. Check Engine and Transmission Mounts: Worn mounts can cause excessive vibration that might exacerbate other issues.
4. Have it Diagnosed: A professional mechanic can perform a proper diagnosis using diagnostic tools to pinpoint the exact problem. This is often the most efficient way to resolve the issue.
Don't continue driving the car if it's stalling when shifting, as you risk causing further damage. Get it towed or have it checked by a mechanic as soon as possible.
