Dashboard light guide · Glass Box Diagnostics
This lamp means continuing to drive can destroy the engine or cost you control of the car. Pull over as soon as it is safe and shut the engine off.
Whether it is a red lamp, a blue-to-red swing, or a needle past the line: overheating is the fastest way a $150 part becomes a $3,000 engine repair. Pull over, assess what is happening under the hood, and never open a hot cap. The cause is always measurable before anyone quotes a new engine.
It-is-the-head-gasket — because a $40 service and a thermostat cannot explain a test the shop never ran. New-engine quote first, cheap tests never.
Typical guess-and-swap cost: $1,800–$4,000 (head gasket/engine guess) when a thermostat, fan relay, or hose was the entire problem
Infrared temperature gun across the radiator (cold spot = flow problem), scan-tool live temp vs. gauge behavior, fan command test, cooling-system pressure test for leaks, combustion-gas test for real gasket failure. Cheap-to-expensive, in that order.
Codes this light commonly sets
Symptoms that come with this light
We come to you — Canyon Lake, San Antonio & Austin. Written report with root cause — see a sample.