1980 BUICK LESABRE

Typical onset: 80,000-120,000 mi

Symptoms: Slipping between gears, especially 1-2 shift, Delayed engagement when shifting into Drive or Reverse, Transmission fluid appears burnt or dark brown, Whining or grinding noises during acceleration

Fix: Full rebuild required in most cases. TH200 units (base V6) are particularly fragile and fail earlier. Expect 12-16 hours labor for a proper rebuild with updated clutch packs, bands, and valve body work. Many shops recommend upgrading to TH350 if starting with TH200.

Estimated cost: $1,800-3,200

Typical onset: 60,000-90,000 mi

Symptoms: White smoke from exhaust, Loss of compression in multiple cylinders, Severe knocking or rattling from bottom end, Coolant mixing with oil (milky dipstick), Head gasket leaks

Fix: The Oldsmobile 350 diesel is notorious for cracked blocks, failed head gaskets, and spun main bearings due to inadequate design. Most need complete engine rebuilds or replacement. Factory blocks often crack between cylinders. Figure 20-30 hours for full rebuild or 12-15 hours for long block swap.

Estimated cost: $3,500-6,500

Typical onset: 100,000-150,000 mi

Symptoms: Deep knocking sound from engine block that increases with RPM, Low oil pressure at idle, Metal shavings in oil filter or on magnetic drain plug, Engine eventually seizes if driven

Fix: Main bearings and rod bearings wear prematurely, especially if oil changes were neglected. Requires crankshaft removal, possible machining, and bearing replacement. If crank journals are scored beyond .030 under, you're looking at crankshaft replacement. 18-24 hours labor for full lower end rebuild.

Estimated cost: $2,200-4,000

Symptoms: Transmission fluid puddles under vehicle, Low transmission fluid level, Hard shifting or slipping after fluid loss, Visible rust or corrosion on steel cooler lines near radiator

Fix: Steel cooler lines rust through at bends and where they connect to radiator. Replace both lines as a pair (one fails, the other is close behind). 2-3 hours labor including fluid refill and leak check. Preventive replacement recommended if you see surface rust.

Estimated cost: $250-450

Symptoms: Hard starting when engine is hot, Fuel smell from engine bay, Engine flooding or excessive fuel consumption, Rough idle or stalling, Black smoke from exhaust

Fix: Rochester Quadrajet and 2-barrel carbs develop stuck floats, worn throttle shafts, and clogged jets from ethanol fuel. Full rebuild with updated parts takes 3-4 hours. Many owners switch to Edelbrock or Holley aftermarket carbs for reliability.

Estimated cost: $400-750

Typical onset: 90,000-130,000 mi

Symptoms: Blue smoke on startup that clears after warmup, Blue smoke during deceleration, Oil consumption 1 quart per 500-800 miles, Carbon buildup on spark plugs

Fix: The Buick 231 V6 burns oil through worn rings and valve seals. Minor cases can limp along with regular oil top-ups, but heavy consumption requires ring replacement and valve seal work. 14-18 hours labor for full ring job with cylinder honing.

Estimated cost: $1,500-2,800

Symptoms: Visible rust through paint on quarter panels and wheel wells, Soft or rotted floor pans, Frame rust near rear axle mounts, Bubbling paint on rocker panels and door bottoms

Fix: These B-bodies rust aggressively in salt states. Rockers, quarter panels, and floor pans go first. Frame usually survives better but check rear spring mounts. Bodywork is labor-intensive; figure 20+ hours for proper rust repair with welding. Many aren't worth saving if rot is extensive.

Estimated cost: $2,000-5,000