What are the most common Toyota Supra problems?
According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 1990-1990 Toyota Supra has 10 documented issues. The most frequently reported are: 7M Head Gasket Failure (BHG) from Under-Torqued Factory Head Bolts, Cam Position Sensor (CPS) Failure — No-Start / No-Spark, Fuel Pulsation Damper Leak on the Fuel Rail (Fire Hazard). Of these, 4 are rated critical and should be addressed promptly.
Is the Toyota Supra reliable?
The 1990-1990 Toyota Supra has 10 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 4 issues are rated critical: 7M Head Gasket Failure (BHG) from Under-Torqued Factory Head Bolts and Cam Position Sensor (CPS) Failure — No-Start / No-Spark and Fuel Pulsation Damper Leak on the Fuel Rail (Fire Hazard) and Chronic Overheating from Air-Pocket-Prone Cooling System and Aged Fan Clutch. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Toyota Supra problems?
Repair costs for known Toyota Supra issues range from $30 to $3,500, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, 7M Head Gasket Failure (BHG) from Under-Torqued Factory Head Bolts, typically costs $1,200-$3,500 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 1986-1992 Toyota Supra 7M Head Gasket Failure (BHG) from Under-Torqued Factory Head Bolts?
The defining flaw of the A70 Supra: Toyota's factory head-bolt torque spec of 58 ft-lb (78 N-m) on the 7M-GE and 7M-GTE was roughly 20-30 ft-lb too low, allowing the composite head gasket to lose clamp and fail prematurely under normal driving. Combustion gases push into the cool… Repairs typically run $1,200-$3,500. Severity: high.
What is the 1986-1992 Toyota Supra Cam Position Sensor (CPS) Failure — No-Start / No-Spark?
The distributor-less 7M uses a dedicated cam position sensor to generate the G and NE signals the ECU needs for spark and injection, and after decades of heat-cycling the sensor's internal windings and its wiring become brittle, corroded, or open-circuit. A failed CPS produces a… Repairs typically run $150-$450. Severity: high.
What is the 1987-1992 Toyota Supra Fuel Pulsation Damper Leak on the Fuel Rail (Fire Hazard)?
The fuel pulsation damper mounted on the 7M-GTE fuel rail (Toyota P/N 23270-42010) commonly develops leaks as its diaphragm ages or as the adjustment screw on top backs out, dripping pressurized fuel onto the hot intake side of the engine. Owners report strong gas smells under th… Repairs typically run $60-$250. Severity: high.
What is the 1986-1992 Toyota Supra Chronic Overheating from Air-Pocket-Prone Cooling System and Aged Fan Clutch?
Beyond the head gasket itself, the 7M cooling system is unforgiving: it traps air pockets if not bled with the correct procedure, and 30-plus-year-old fan clutches, corroded radiators, and missing fan shrouds are common causes of creeping temperatures. Because the engine 'does no… Repairs typically run $100-$900. Severity: high.
What is the 1987-1992 Toyota Supra Progressive Power Steering (PPS) Faults and Rack Leaks?
Turbo-model MK3s use a Progressive Power Steering rack with an ECU/speed-sensor-controlled solenoid that firms up assist at highway speed, and the system fails in two ways: erratic assist (steering randomly firming and softening from bad speed-sensor signals or wiring) and hydrau… Repairs typically run $200-$1,200. Severity: medium.
What is the 1987-1992 Toyota Supra Stock CT26 Turbocharger Wear — Shaft Play and Oil Smoke?
The 7M-GTE's stock Toyota CT26 turbo is now well past its design life on surviving cars: worn journal bearings produce shaft play, oil leaks past the seals into the compressor inlet and intercooler piping, and blue smoke appears under or just after boost. The 7M's stock PCV routi… Repairs typically run $400-$2,000. Severity: medium.
What is the 1986-1992 Toyota Supra ECU Electrolytic Capacitor Leakage — Rough Idle, Stalling, No-Start?
The original electrolytic capacitors in the MK3's engine ECU leak electrolyte with age, heat, and power cycles, and the spilled electrolyte etches the copper traces on the circuit board, eventually shorting or open-circuiting the ECU. Symptoms start as odd running behavior — roug… Repairs typically run $30-$350. Severity: medium.
What is the 1986-1992 Toyota Supra Rear Hatch Strut Failure?
The gas struts supporting the MK3's large, heavy glass hatch lose pressure with age, leaving the hatch unable to stay open — a near-universal annoyance on surviving cars and a head-knock hazard while loading. Replacement is mechanically simple but access to the upper mounting nut… Repairs typically run $50-$150. Severity: low.
What is the 1986-1992 Toyota Supra Dashboard Cracking?
MK3 dashboards crack with near-universal regularity, typically across the top pad above the instrument cluster and defroster vents, driven by UV exposure and the vinyl-over-foam construction drying out with age (silicone-based dressings are widely blamed for accelerating it). It… Repairs typically run $50-$800. Severity: low.
What is the 1986-1992 Toyota Supra Targa Top Water Leaks?
Sport-roof (targa) MK3s commonly leak water into the cabin headliner, footwells, and seats as the targa weatherstrips harden and, more often, as the factory sealant between the removable panel and its seal-rail (held by four screws) fails. Forum consensus is that many 'bad seal'… Repairs typically run $50-$450. Severity: low.
