The 1991 NSX is Honda's hand-built exotic with legendary reliability for its class, but age is the real enemy now. These 30+ year-old cars face wear items that are expensive due to aluminum-intensive construction, mid-engine layout complexity, and discontinued parts.
Snap Ring Transmission Failure
Occasional · high severityTypical onset: any mileage on VINs MT000001-MT002300
Symptoms: Transmission pops out of gear under load, especially 2nd gear, Complete loss of all gears if snap ring breaks, No warning in many cases—sudden catastrophic failure
Fix: Engine-out job to replace snap ring with updated part. 16-20 hours labor minimum due to mid-engine access. Many owners upgrade clutch and other wear items while transmission is out. Only affects early 5-speed manuals in specific VIN range.
Estimated cost: $3,500-6,000
Cooling System Hose Failures
Common · high severityTypical onset: any original hoses over 20 years old
Symptoms: Coolant weeping from hose connections or hose bodies, Sudden coolant loss while driving, Overheating if main hoses fail, Multiple small-diameter hoses crack internally first
Fix: Mid-engine layout makes several hoses difficult to access—some require removing engine cover, intake components, or working blind. The car has 15+ coolant hoses; doing them all at once requires 6-8 hours. Factory hoses are NLA for many sections; owners use custom silicone replacements.
Estimated cost: $1,200-2,500
Main Relay Solder Joint Failure
Common · medium severityTypical onset: not mileage-dependent, age and heat-related
Symptoms: No-start condition when engine is heat-soaked, Starts fine cold, won't start after short drives, Fuel pump doesn't prime on hot restarts, Intermittent gauge cluster issues
Fix: Classic Honda issue. Main relay is under driver's side dashboard. Remove relay, open case, resolder cracked joints on circuit board. 0.5 hours labor if you know what you're doing. Many owners send to specialist for $75-150 rework or buy remanufactured unit.
Estimated cost: $150-350
Window Regulator Failures
Common · low severityTypical onset: 80,000-150,000 mi
Symptoms: Window moves slowly or stops mid-travel, Grinding or clicking noise when operating windows, Window drops into door or won't stay up, Plastic regulator guides crack with age
Fix: Door panel removal and regulator replacement. 2-3 hours per side due to tight mid-engine cockpit access. OEM regulators are discontinued; aftermarket quality is inconsistent. Some owners retrofit upgraded metal guides.
Estimated cost: $600-1,200
Climate Control Unit LCD Failure
Common · low severitySymptoms: Climate control display is blank or shows partial segments, HVAC still functions but you can't see settings, Display fades in hot weather, may return when cool
Fix: LCD panels from this era commonly fail. Unit must be removed from center console (1 hour) and sent to specialist for screen replacement and capacitor refresh ($200-400 rebuild cost). No driving impact but annoying quality-of-life issue.
Estimated cost: $400-700
Timing Belt and Water Pump Service
Common · high severityTypical onset: every 60,000-90,000 mi or 6-7 years
Symptoms: No symptoms until failure, which destroys engine (interference design), Water pump bearing noise if that fails first, Belt age cracking visible on inspection
Fix: This is the big service. Timing belt, tensioners, water pump, accessory belts, valve cover gaskets all done together. Mid-engine location and transverse V6 make access tedious—expect 8-12 hours. If valve adjustment or cam seals needed, add 2-3 hours. Skipping this service risks $15k+ engine damage.
Estimated cost: $2,000-3,500
ABS Modulator Failure
Occasional · medium severitySymptoms: ABS warning light stays on, No ABS function but normal braking works, Modulator motor makes noise or doesn't run on startup test
Fix: Early ABS system with poor parts availability. OEM modulators are discontinued. Rebuilt units available from specialists for $800-1,200. Installation is straightforward—2 hours labor—but requires brake bleeding. Some owners delete ABS entirely rather than repair.
Estimated cost: $1,200-2,000
Buy one if you can afford specialist maintenance and accept that 30-year-old exotic car problems cost exotic car money, even with Honda reliability baked in.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.