Q: Heater works randomly in my lexus es350...any ideas??

Hi there. If the thermostat is damaged or faulty, it would typically create an overheating problem associated with the heater’s failure to blow hot air. Sometimes this issue can be caused by an obstruction inside the heater core. Sometimes flushing the coolant system will resolve this problem. It may also be possible the temperature control valve is damaged. You might want to have a professional mechanic come to your location and complete a heater is not working inspection.

Hi there. It sounds like there may be a low coolant level affecting the heater in you Lexus. Perform a visual inspection of the coolant level when the vehicle is cold; check the reservoir bottle and the radiator. If the coolant level is low, then there is most likely a leak that would need further investigation. I suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a heater is not working inspection.