1990 MAZDA RX-7

Typical onset: 80,000-120,000 mi

Symptoms: Hard starting when warm, White smoke on deceleration, Loss of power especially at high RPM, Failed compression test showing under 90 psi per rotor face, Excessive oil consumption beyond the normal 1 qt per 1,000 mi

Fix: Full rotary rebuild required: tear down engine, replace apex seals, side seals, corner seals, all gaskets, resurface housings if not cracked. Figure 25-35 labor hours for complete rebuild at a rotary-experienced shop. Many owners opt for streetport or modifications during rebuild since it's apart anyway. DIY possible but requires specialized tools and meticulousness.

Estimated cost: $3,500-6,500

Typical onset: 100,000-140,000 mi

Symptoms: Loud whistling or grinding noise from turbo, Blue smoke on boost, Oil leaking from turbo drain line, Sluggish acceleration and boost creep, Shaft play visible when wiggling compressor wheel

Fix: Replace turbocharger assembly. OEM turbos are NLA so aftermarket or rebuild required. While you're in there, replace all vacuum lines (they're 30+ years old), oil feed and drain lines, and inspect intercooler for leaks. 8-12 hours labor including proper cooldown procedure setup.

Estimated cost: $1,200-2,800

Symptoms: Transmission fluid puddles under car near radiator, Low transmission fluid despite no visible external leak at pan, Coolant smells burnt or has pink tinge, Transmission slipping after engine reaches operating temp

Fix: Metal lines rust through where they connect to radiator-mounted cooler. Replace cooler lines and external transmission cooler if mixing occurred. Flush cooling system and transmission completely. If coolant entered transmission, rebuild becomes necessary. Line replacement alone: 3-4 hours.

Estimated cost: $400-800

Symptoms: Temperature gauge climbing past halfway, Coolant overflow tank bubbling or puking, Heater blowing cold at idle, Twin turbo models running hotter on driver side, White residue around radiator cap

Fix: Rotaries are heat-sensitive and the cooling system is complex with multiple thermostats and routing. Common culprits: original radiator clogged internally, water pump impeller corroded, air pockets from improper bleeding, failed thermostat. Full system service includes radiator replacement (often upgraded to aluminum), new water pump, both thermostats, all hoses, proper bleeding procedure. 6-10 hours depending on scope.

Estimated cost: $800-1,800

Symptoms: Erratic idle or high idle, Check engine light with codes for air/fuel mixture, Boost gauge reading incorrectly or turbo not building boost, Hissing sounds from engine bay, Poor fuel economy

Fix: The vacuum system on these is a rats nest of 30-year-old rubber lines controlling everything from turbo wastegate to emissions. Replace ALL vacuum lines as preventive maintenance—they crack and collapse internally. Use silicone vacuum line and label everything during removal. Patient 4-6 hours if done methodically with diagram.

Estimated cost: $200-450

Typical onset: 90,000-150,000 mi

Symptoms: Clunking over bumps from rear, Rear end feels loose or darty during cornering, Visible cracks in rubber bushings during inspection, Uneven rear tire wear especially inside edges, Toe alignment won't hold settings

Fix: Rear trailing arm bushings are known weak point and affect the brilliant handling these cars are known for. Replace all rear bushings as a set: trailing arm, lateral link, upper control arm. Urethane upgrades common. Requires press and alignment afterward. 5-7 hours plus alignment.

Estimated cost: $600-1,200

Typical onset: 100,000+ mi

Symptoms: Hesitation or stumble under acceleration, Hard starting after sitting, Fuel smell in cabin or garage, Fuel pressure not reaching spec 30-36 psi, Running lean codes on aftermarket ECU

Fix: Fuel filter is non-serviceable in-tank type and gets clogged. Fuel pump often weak. Injectors need cleaning or replacement. Steel fuel lines under car rust in salt states. Comprehensive fix: drop tank, replace pump and filter sock, clean injectors, replace rubber fuel lines. 6-9 hours labor.

Estimated cost: $700-1,400