At higher mileages (125,000+) the Engine Coolant Temperature Sensor may intermittently stop working, especially when the vehicle is fully warmed up. This can cause the engine to stall unexpectedly.
Toyota Supra Problem Reports
RepairPal Verified Toyota Supra Problem Reports
At higher mileages, (125,000-150,000) the automatic transmission may not shift correctly. This can be caused by the throttle position sensor being out of adjustment or a shift solenoid needing to be replaced. Typically the transmission does not need to be completely overhauled.
The Throttle Position Sensor can get out of adjustment due to wear in the throttle body or due to carbon build up. This will cause the idle timing to advance more than 30 degrees which will cause very high HC and NOx emissions. Conversely, the Throttle Position Sensors can wear out and not properly advance the timing which causes a lack of power and poor fuel economy.
Our technicians tell us that it is important to change the coolant with factory coolant and replace the thermostat every 60,000 miles. This will help to protect the head gasket, otherwise the head gasket can deteriorate and be stressed to the point of failure.