1968 BUICK LESABRE

Typical onset: 80,000-130,000 mi

Symptoms: Slipping between low and direct gear, especially under load, No movement in reverse or delayed engagement, Transmission overheating, fluid smells burnt, Clunking or harsh shifts when cold

Fix: The two-speed automatic is notorious for clutch pack wear and inadequate cooling. Rebuild requires 8-12 hours labor; external cooler addition highly recommended during rebuild. Transmission mounts often collapse simultaneously, adding another hour.

Estimated cost: $1,800-3,200

Typical onset: 100,000-150,000 mi

Symptoms: Heavy knocking from crankcase, worse under load or acceleration, Low oil pressure at idle (under 10 psi hot), Metallic debris in oil filter, Rapid oil consumption without visible external leaks

Fix: Main and rod bearings wear due to marginal oil pump capacity and clogged oil galleries. Requires crankshaft removal, measuring, possible turning, new bearings, and reassembly. 18-24 hours labor for in-chassis crank R&R; full short-block replacement runs 22-28 hours if machine work needed.

Estimated cost: $2,800-5,500

Typical onset: 90,000-140,000 mi

Symptoms: Blue smoke on startup and heavy throttle, Burning through 1+ quart of oil every 500-800 miles, Poor compression readings (below 120 psi), Carbon buildup on spark plugs

Fix: Ring lands carboned up, rings stick or lose tension. Proper fix is piston/ring replacement with cylinder honing—20-26 hours labor. Many owners limp along adding oil, but this accelerates catalytic converter death (if equipped) and fouls plugs constantly.

Estimated cost: $2,200-4,000

Symptoms: Hard starting when hot, fine when cold, Flooding, fuel smell, or drips from carb base, Flat spot or hesitation on acceleration, Rough idle that improves once warmed up

Fix: The Rochester 2GC or 4GC carburetors use brass floats that develop pinholes or accelerator pumps that dry-rot. Rebuild kit and 2-3 hours labor usually resolves it. Ethanol fuel accelerates deterioration.

Estimated cost: $250-500

Typical onset: 60,000-100,000 mi

Symptoms: Transmission fluid puddles under front of vehicle, Fluid level drops, leading to slipping or overheating, Rusty or corroded steel cooler lines along frame rail

Fix: Steel lines rust through where they clip to the frame or connect to radiator. Replacement lines and fittings run 2-3 hours labor. Critical to catch early—low fluid will cook the transmission.

Estimated cost: $300-600

Symptoms: Intermittent no-start or dying at idle, Misfiring under load, especially when hot, Weak spark visible during testing, Rough running that clears up temporarily after revving

Fix: Points pit and condenser fails, typical of all non-electronic ignition systems. Replacement every 12,000-15,000 miles or annually. Takes 0.5-1 hour with dwell/timing adjustment. Many owners convert to electronic ignition module to eliminate this maintenance.

Estimated cost: $80-180