The 1974 Buick Apollo, a rebadged Nova on GM's X-body platform, is mechanically simple but shows its age in powertrain durability and emissions-era carburetion issues. The TH350 automatic is generally solid, but engine longevity varies wildly with maintenance history.
Worn Engine Internals (Rings, Bearings, Crankshaft)
Common · high severityTypical onset: 90,000-140,000 mi
Symptoms: Excessive oil consumption (1 qt per 500-800 miles), Blue smoke on startup and acceleration, Low compression across multiple cylinders, Knocking or rattling from crankcase, Metal particles in oil
Fix: Full engine rebuild required: pull engine, machine block and crank, replace rings, bearings, gaskets, seals. 18-24 labor hours for complete rebuild. Short block replacement takes 12-16 hours if you source a core.
Estimated cost: $2,800-5,500
Carburetor Issues and Lean Running (Rochester 2GC/2GV)
Common · medium severitySymptoms: Hard starting when warm, Stalling at idle or when cold, Hesitation on acceleration, Poor fuel economy below 10 mpg, Backfiring through carb
Fix: Emissions-era carbs have vacuum lines, EGR passages, and jets that clog or fail. Full rebuild kit plus adjustment takes 3-4 hours. Many shops just replace with remanufactured unit (2 hours install).
Estimated cost: $350-750
TH350 Transmission Slipping and Seal Leaks
Occasional · medium severityTypical onset: 100,000-150,000 mi
Symptoms: Delayed engagement into drive or reverse, Slipping between 1st and 2nd gear, Transmission fluid leaking from front seal or pan, Burnt smell from fluid, Harsh or late shifts
Fix: Minor leaks: reseal pan and replace modulator (2-3 hours, $150-300). Slipping requires full rebuild with clutches, bands, seals—8-12 hours labor. TH350s are rebuildable but require experienced tech.
Estimated cost: $1,200-2,400
Rusted Body Mounts and Frame Perimeter Rails
Common · high severitySymptoms: Clunking when hitting bumps, Doors misaligning or hard to close, Visible rust or separation at body mount points, Flexing body panels, Sagging rear quarter panels
Fix: Rust belt cars often have compromised mounts and frame. Replacing all body mounts takes 6-8 hours. Frame rust may be unrepairable or require expensive plating/welding. Inspect before purchase.
Estimated cost: $600-1,200
Fuel System Degradation (Tank, Lines, Filter)
Occasional · medium severitySymptoms: Fuel starvation under load, Hard starting after sitting, Fuel smell in cabin or trunk, Visible rust particles in filter, Fuel gauge erratic or non-functional
Fix: Original steel tanks rust from inside out after 40+ years. Tank replacement with new sending unit: 4-5 hours. Replace all rubber fuel lines at same time (another 2 hours). Filter is inline, easy swap.
Estimated cost: $450-900
Steering Box Wear and Excessive Play
Occasional · medium severityTypical onset: 80,000-120,000 mi
Symptoms: More than 2 inches of play at wheel rim, Wandering on highway, Clunking when turning lock-to-lock, Leaking gear oil from steering box
Fix: Saginaw manual or power boxes can be adjusted (1 hour) if not worn internally. Replacement with rebuilt unit: 3-4 hours labor. Inspect pitman arm and idler arm simultaneously—often worn together.
Estimated cost: $350-700
Buy only with documented engine rebuild or verifiable low-mileage history; most survivors need $3,000-5,000 in deferred powertrain work, and rust is the silent killer.
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.