* Low Transmission Fluid: Check your transmission fluid level immediately. Low fluid can cause all sorts of problems, including stalling when engaging the gear. If it's low, you'll need to add fluid, but also investigate *why* it's low (leak, etc.).
* Transmission Problems: A failing transmission is a serious possibility. This could involve worn clutches, a failing torque converter, or internal transmission issues. This is usually accompanied by other symptoms like slipping gears, rough shifting, or noises from the transmission.
* Torque Converter Issues: The torque converter connects the engine to the transmission. A malfunctioning torque converter can prevent proper power transfer, leading to stalling.
* Engine Issues: While less likely to cause stalling *only* when shifting into gear, problems like a failing ignition system (coil, wires, distributor cap/rotor), a vacuum leak, or low fuel pressure can also contribute. These issues might cause general engine hesitation or misfires that are exacerbated under load when engaging the gear.
* Clutch (If Manual): If it's a manual transmission, the clutch may be worn, improperly adjusted, or have other issues preventing proper engagement.
* Shift Linkage/Cable: Problems with the linkage or cable that controls gear selection could prevent the transmission from properly engaging.
* Computer/Sensor Issues: A faulty sensor (like a crankshaft position sensor or throttle position sensor) can provide inaccurate data to the engine computer, leading to stalling.
What to do:
1. Check the transmission fluid: This is the easiest and cheapest first step. Consult your owner's manual for the correct procedure and fluid type.
2. Listen for unusual noises: Pay attention to any grinding, whining, or knocking sounds coming from the transmission when shifting or driving.
3. Check for error codes: Use an OBD-II scanner to check for diagnostic trouble codes (DTCs) stored in the car's computer. These codes can point to specific problems.
4. Have it professionally diagnosed: If the problem persists after checking the fluid and listening for noises, it's crucial to take your Cavalier to a qualified mechanic. They have the tools and expertise to properly diagnose the issue and perform the necessary repairs. Improper diagnosis and repair of transmission problems can lead to significant further damage and expense.
Ignoring this issue can lead to more severe damage and expensive repairs. Get it checked out soon!
