Possible Causes:
* Automatic Transmission Issue: The most likely culprit is a problem with your automatic transmission. Here's why:
* Torque Converter Lockup Issue: The torque converter allows the engine to run independently of the wheels when the vehicle is stationary. If it fails to lock up properly when you shift into gear, the engine will continue to run.
* Internal Transmission Problems: A faulty transmission valve body, worn clutches, or other internal damage can cause slippage and prevent the transmission from engaging fully, leading to the engine staying running.
* Engine Problems:
* Idle Air Control (IAC) Valve: This valve regulates the amount of air entering the engine at idle. If it's malfunctioning, the engine might not idle properly, leading to it staying running even when the transmission should be engaging.
* Other Factors:
* Faulty Neutral Safety Switch: This switch prevents the engine from starting unless the transmission is in "Park" or "Neutral." A malfunctioning switch could allow the engine to run even when the transmission is in gear.
* Wiring Issues: A short circuit or open wire in the transmission or engine control systems could also be causing the problem.
What to Do:
1. Check the Transmission Fluid: Make sure the transmission fluid level is correct and the fluid isn't burnt or discolored.
2. Inspect for Leaks: Look for any transmission fluid leaks.
3. Test the Neutral Safety Switch: If you're comfortable with basic car maintenance, you can test the switch with a multimeter.
4. Have the Transmission Inspected: If you suspect a transmission issue, take your Silverado to a trusted mechanic for a thorough inspection. They can diagnose the problem and recommend repairs.
5. Check the Engine Idle: Make sure the engine is idling smoothly and at the correct RPM when in "Park" or "Neutral." If it's idling too high or low, it could be a sign of an engine problem.
Important Note: It's crucial to get your vehicle diagnosed by a qualified mechanic to determine the root cause of the problem. Driving with a faulty transmission or engine could lead to further damage and potentially dangerous situations.
