My car has only 15,000 miles and it has been showing check engine light on. When it happens, the temperature goes to hot and quickly goes back down. When I start decelerating, the engine gets very noisy and the car starts shuddering and turns off. I've got codes indicating low voltage from the coolant temperature. I've had cylinder 1 and 2 compression tested and it is all fine. What could be the problem?
Fault codes need to be read out from the engine computer. There is a technical service bulletin (TSB) out by Lexus that points to a faulty thermostat causing a Check Engine Light, and that the thermostat should be replaced based on the fault codes stored. The engine coolant would need to be drained, refilled, and then bled after the repair. You may want to enlist the help of a mechanic, such as one from YourMechanic, who will have the tools and training to complete this repair. Please note: never attempt to service the engine cooling system while the engine is hot or the system is pressurized, as doing so could result in serious injury.