Likely due now$450-$850
Timing belt + water pump service
What you’ll notice: No symptom until it fails. This is interval maintenance. No receipts means it's due.
60k-mile interval on the B-series engine. Sellers routinely can't prove it was done; if there's no receipt, assume it's due. Usually bundled with cam/crank seals and accessory belts.
Parts $150-$325 · Labor 2-3.5h ($300-$525 @ $150/hr) · Weekend DIY
Typical window: 60k-90k miles · add mileage to sharpen this
Source: Mazda factory service interval; Miata.net DIY guides · estimate, pending verification
Likely due now$475-$1,250
Soft top and rear window replacement
What you’ll notice: Shrunken top that fights the latches, split seams, yellowed or cracked plastic rear window, water stains on carpet.
Original tops are 20+ years old. A leaking top also feeds the rust problem above.
Parts $250-$650 · Labor 1.5-4h ($225-$600 @ $150/hr) · Advanced DIY
Typical window: 15-35 years of age · add mileage to sharpen this
Source: Age-driven consumable; Miata.net top-replacement guides · estimate, pending verification
Likely due now$700-$1,650
Shocks, springs, and bushings past their life
What you’ll notice: Floaty ride, clunks over bumps, uneven tire wear, original-dated dampers.
Most survivors ride on original or worn-out cheap dampers. A full refresh transforms the car and is the most commonly needed big-ticket item after rust.
Parts $400-$900 · Labor 2-5h ($300-$750 @ $150/hr) · Weekend DIY
Typical window: 90k-150k miles · add mileage to sharpen this
Source: Community consensus; age/mileage-driven wear item · estimate, pending verification
Likely due now$135-$420
Clutch slave / master cylinder
What you’ll notice: Soft or sinking clutch pedal, slow pedal return, fluid weeping at the slave.
The slave cylinder is a known consumable. Cheap part, common failure, often deferred by sellers.
Parts $60-$120 · Labor 0.5-2h ($75-$300 @ $150/hr) · Easy DIY
Typical window: 80k-130k miles · add mileage to sharpen this
Source: Miata.net common-failures lists · estimate, pending verification
Likely due now$65-$255
Valve cover gasket & cam angle sensor O-ring leaks
What you’ll notice: Oil seepage down the back of the engine, faint burning-oil smell after driving.
Classic B-series seepage points. Cheap fixes, but oil on the exhaust manifold smokes and scares buyers. Good bargaining material more than a real problem.
Parts $20-$60 · Labor 0.3-1.3h ($45-$195 @ $150/hr) · Easy DIY
Typical window: 70k-120k miles · add mileage to sharpen this
Source: Miata.net common-failures lists · estimate, pending verification
Inspect for itDeal-shaper$800-$3,500
Rust in rocker panels and frame rails
What you’ll notice: Bubbling paint low on the sills, crusty metal behind the plastic sill covers, damp carpets after rain.
Soft-top drains clog and dump water into the sills. Rot hides behind plastic sill covers, so a shiny car can still be structurally crusty underneath. This is the #1 Miata deal-breaker.
Parts $200-$800 · Labor 4-18h ($600-$2,700 @ $150/hr) · Shop job
Condition-driven: inspect, don't assume · cost applies only if found (excluded from headline budget)
Source: Miata.net community consensus; universal PPI guidance for NA/NB · estimate, pending verification
Inspect for itDeal-shaper$550-$2,550
Short-nose crank keyway wear (1990-91 1.6L)
What you’ll notice: Crank pulley wobbles visibly at idle; ticking from the front of the engine.
Early 1.6 cranks have a shorter snout; a loose crank bolt lets the keyway wallow out. A wobbling crank pulley on an early car can mean a new crank or engine.
Parts $100-$900 · Labor 3-11h ($450-$1,650 @ $150/hr) · Shop job
Condition-driven: inspect, don't assume · cost applies only if found (excluded from headline budget)
Source: Miata.net 'short nose crank' documentation (1.6L 1990-91 only) · estimate, pending verification