* Low Transmission Fluid: Check your transmission fluid level immediately. Low fluid is a very common cause of overheating and subsequent transmission failure. If it's low, find out *why* it's low. A leak is a serious issue. The color and smell of the fluid are also important; burned fluid (dark brown or black, burnt smell) indicates significant internal damage.
* Transmission Fluid Cooler: The transmission fluid cooler (often integrated into the radiator) may be clogged or malfunctioning. This prevents the fluid from adequately cooling, leading to overheating and the symptoms you're experiencing.
* Internal Transmission Problems: Overheating could indicate a more serious internal problem within the transmission itself, such as worn clutch packs, a failing torque converter, or other internal components. This is the more expensive and potentially devastating scenario.
* Transmission Solenoid: A faulty solenoid could be intermittently causing the transmission to disengage. This is less likely than fluid issues, but possible.
What to do:
1. Check the transmission fluid level and condition immediately. This is the *first* step. Use the correct procedure for your Blazer's transmission (automatic transmission fluid dipstick, often checked with the engine running and in park).
2. If the fluid level is low, *do not drive the vehicle* until the leak is identified and fixed. Driving with low transmission fluid can cause catastrophic damage.
3. If the fluid level is correct but dark/burnt, have the transmission professionally inspected. This indicates severe internal damage.
4. If the fluid level is okay and looks relatively clean, suspect the transmission cooler. A mechanic can test this.
Do not continue driving the vehicle extensively with this problem. Continuing to drive will likely worsen the damage and lead to a more expensive repair. The short-term fixes (waiting for it to cool) are only masking the underlying issue. Get it checked by a qualified mechanic specializing in automatic transmissions as soon as possible. They have the tools to diagnose the problem accurately and provide an appropriate repair.
