Here are some of the possibilities:
* Transmission problems: The grinding noise strongly points to a transmission issue. This could be low transmission fluid, worn-out gears, a failing clutch (if manual), or a problem with the transmission's internal components. Low fluid could be a relatively inexpensive fix, but major transmission repairs are very expensive.
* Engine problem: The engine light could be related to the transmission issue (e.g., a sensor detecting a problem), or it could be a separate engine problem that's indirectly causing the grinding. This needs to be diagnosed.
* Driveshaft or axle issues: While less likely to cause an engine light, a problem with the driveshaft or axles *could* create a grinding noise and possibly trigger an engine light due to sensor malfunctions.
What you should do:
1. Stop driving the car immediately. Further driving could worsen the damage and lead to a more expensive repair or even a complete transmission failure.
2. Have the car towed to a qualified mechanic. Don't attempt to diagnose or repair this yourself unless you have extensive automotive experience.
3. Describe the symptoms clearly to the mechanic: Tell them about the engine light, the grinding noise (when it happens – only during gear changes, or constantly?), and the mileage at which the problem occurs.
The mechanic will need to diagnose the problem using a code reader for the engine light and a thorough inspection of the transmission and related components. Be prepared for a potentially expensive repair, especially if the transmission needs significant work. Get multiple estimates if possible.
