1992 Toyota Supra Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 1992 Toyota Supra
Verified by mechanics, reported by drivers like you
1992 Toyota Supra ProblemsOverheating and Sweet Smell Around Engine
The Toyota Supra and Supra Turbo from 1986-1992 (MKIII) is known to leak engine coolant and overheat due to a leaky heater control valve. Drivers will notice a decrease in heater performance, and increase in engine temperature.
The purpose of this valve is to control the amount of heat that enters the cabin of the vehicle. If this valve has failed, it is recommended to use the OEM part for replacement.
Please note, the engine in both versions of the 1986-1992 Supra is prone to head gasket failure, so it is imperative that any coolant issues are addressed immediately to avoid costly repairs.
The third-generation (MKIII) Toyota Supra has a common problem with the rear hatch leaking water into the vehicle.
Through normal operation, dirt, leaves, or twigs will build up between the hatch and the body causing the hatch seal to deteriorate at a rapid pace. As the problem worsens, the hatch will develop water leaks, and wind noise in the rear of the car will increase. If this issue goes unchecked, rust will begin to develop in the spare tire compartment, and around hatch.
The solution is to replace the rear hatch seal, and thoroughly clean and wax the body where the seal makes contact. If rusting has already begun, the body will require repair.
To help prevent the issue, frequently clean any debris build-up between the hatch and body.
The 1986-1992 Toyota Supra and Toyota Supra Turbo may lose power, fuel economy, and possibly have black smoke from the tail pipe due to a known issue with the knock sensor and/or knock sensor wiring harness.
The knock sensor is mounted to the engine, and detects knocking and pinging conditions which may harm the engine. When the knock sensor malfunctions, engine performance is decreased and fuel consumption is increased causing 'rich' running conditions. The check engine light is associated with OBD Trouble Code 52.
There are two common fixes for this issue: Inspect/repair sensor wiring harness, and test/replace knock sensor.