Symptoms of a failing transmission in a Grand Am (or any car):
* Slipping: The engine revs up, but the car doesn't accelerate proportionally. This is a classic sign of worn clutches or bands inside the transmission.
* Hard shifts: Sudden, jarring shifts between gears.
* Delayed shifts: A noticeable lag between when you shift and when the gear engages.
* Whining, grinding, or humming noises: Unusual sounds coming from the transmission area, especially during acceleration or deceleration.
* Fluid leaks: Look for reddish-brown fluid leaks under the car. Transmission fluid is crucial, and a leak indicates a problem.
* Inability to shift into gear: Difficulty selecting a gear, or the gear not engaging properly.
* Overheating: The transmission overheating and possibly even burning the fluid is a serious sign.
Why stalling after high-speed driving might *not* be the transmission:
* Low or dirty transmission fluid: This can cause poor shifting and potentially stalling. Check your fluid level and condition. It should be a clear reddish color and not smell burnt.
* Faulty speed sensor: A malfunctioning speed sensor can send incorrect signals to the transmission control module (TCM), leading to erratic behavior, including stalling.
* Brake system issues: If your brakes are dragging or applying intermittently, it can put stress on the engine and potentially cause stalling, especially when slowing down from high speed.
* Engine problems: Stalling can be caused by issues within the engine itself, such as a failing ignition system, fuel delivery problem, or other mechanical issues. This is a broad category requiring further diagnostics.
* Computer problems (TCM/PCM): Issues with the transmission control module (TCM) or Powertrain Control Module (PCM) could lead to erratic transmission behavior and stalling.
What to do if your Grand Am stalls after high-speed driving:
1. Check your transmission fluid: Check the level and condition of the fluid. If it's low, dark, burnt, or smells unusual, you have a problem that needs immediate attention.
2. Have it professionally diagnosed: The stalling after high-speed driving, coupled with any of the other transmission symptoms listed above, warrants a visit to a mechanic or transmission specialist. They have the tools and expertise to properly diagnose the problem and determine if it's the transmission or something else. Don't attempt significant repairs yourself unless you have extensive automotive experience.
In short, while stalling after high speeds *could* indicate a failing transmission, it's not definitive. A professional diagnosis is essential to pinpoint the exact cause and prevent further damage to your vehicle.
