1957 CADILLAC COUPE DE VILLE

Typical onset: 80,000-150,000 mi on original or poorly-rebuilt engines

Symptoms: Heavy oil consumption (1+ quart per 500 miles), Rod knock or main bearing rumble at idle, Low oil pressure at operating temperature (under 15 psi), Blue smoke on deceleration, Metal shavings in oil filter

Fix: Full engine rebuild required. Short block minimum means pulling engine, complete disassembly, crank turning or replacement, new bearings, pistons, rings, timing set. Plan 40-60 labor hours for removal, rebuild, and reinstallation. Original blocks can crack if overheated previously—inspection critical.

Estimated cost: $6,500-12,000

Typical onset: Not mileage-dependent—age and lack of cooler maintenance are primary factors

Symptoms: Transmission fluid burning smell, Leaking from front pump seal or tail housing, Delayed engagement when cold, Slipping between 2nd and 3rd gear under load, Dark or burnt-smelling fluid

Fix: Trans oil cooler lines corrode internally and restrict flow. External cooler lines and cooler itself need replacement. Front pump seal replacement requires transmission removal (12-16 hours). Full rebuild if internal damage from overheating already occurred—add 20+ hours. These four-speed Hydra-Matics are rebuildable but parts availability varies.

Estimated cost: $800-1,500 for cooler system; $3,500-6,000 for full rebuild

Typical onset: 100,000+ mi or after multiple clutch-style parking pawl engagements

Symptoms: Excessive crankshaft endplay (over 0.012 inches), Metallic scraping noise during startup, Clutch chatter feel through drivetrain (even though automatic), Oil leak from rear main seal area

Fix: Requires complete engine removal and disassembly to replace thrust bearings—same job as full rebuild. Crankshaft may need machining if thrust surfaces scored. Not a standalone repair; budget for short block minimum. 35-50 labor hours.

Estimated cost: $5,500-9,500

Symptoms: Hard starting when hot, Fuel smell in garage after sitting, Idle surging or stalling, Black smoke and poor fuel economy, Gas leaking from carburetor base or fuel pump

Fix: Original Carter or Rochester four-barrel carburetors gum up from modern ethanol fuel. Complete rebuild kit installation takes 4-6 hours including removal, disassembly, cleaning, reassembly, and tuning. Fuel pump diaphragms deteriorate—another 2 hours. Replace all rubber fuel lines from tank forward (they're 65+ years old). In-line fuel filter mandatory.

Estimated cost: $800-1,800

Symptoms: Clunk when shifting from Park to Drive or Reverse, Excessive drivetrain vibration at idle in gear, Visible transmission sag when inspected on lift

Fix: Rubber transmission mounts deteriorate even on garaged cars. Replacement requires supporting transmission with jack, removing two mount bolts per side. 2-3 hours labor. Inspect engine mounts simultaneously—they fail at similar rates.

Estimated cost: $350-650

Symptoms: Persistent overheating in traffic or summer heat, Coolant weeping from block freeze plug areas, External coolant leaks with no obvious hose failure, Milky oil (if crack reaches oil galley)

Fix: Original two-row radiators marginal for modern traffic. Re-core or replacement with three-row mandatory (4-6 hours). If block already cracked between cylinders or at freeze plugs, requires block replacement or professional welding repair—essentially a full engine-out rebuild scenario.

Estimated cost: $600-1,200 for radiator; $7,000-13,000 if block cracked