The 1980 Buick Skylark, built on GM's X-body platform, suffers from significant powertrain durability issues, particularly with the Iron Duke 151 four-cylinder and early 173 V6 engines that developed catastrophic internal failures surprisingly early in their service life.
151ci Iron Duke Connecting Rod Bearing Failure
Common · high severityTypical onset: 60,000-90,000 mi
Symptoms: heavy knocking from lower engine, especially when cold, metallic rattling that increases with RPM, sudden oil pressure drop, metal shavings in oil during changes
Fix: Rod bearings fail prematurely due to marginal oiling and weak connecting rods. Requires engine removal, full teardown, rod and main bearing replacement, crankshaft inspection and possible regrind. 18-24 labor hours for full bearing job. Many shops recommend short block replacement instead due to collateral damage.
Estimated cost: $2,200-3,800
173ci V6 Crankshaft Failure
Occasional · high severityTypical onset: 70,000-110,000 mi
Symptoms: catastrophic knocking noise, engine seizes suddenly, loss of oil pressure, visible metal contamination in oil pan
Fix: Early 173 V6 cranks were insufficiently hardened and would crack or twist main journals. Requires complete engine removal and either crankshaft replacement with machine work or short block swap. 20-28 hours for R&R and rebuild. Most owners go with junkyard engine swap at this point.
Estimated cost: $2,800-4,500
Transmission Mount Collapse
Common · medium severityTypical onset: 50,000-80,000 mi
Symptoms: severe clunking when shifting into drive or reverse, excessive engine movement visible from driver seat, vibration at idle in gear, difficulty shifting smoothly
Fix: Rubber transmission mounts deteriorate rapidly on X-body cars due to poor material quality and engine vibration from the rough Iron Duke. Requires lift access, transmission support, and mount replacement. 2-3 hours labor. Often accompanied by deteriorated engine mounts.
Estimated cost: $180-350
Transmission Oil Cooler Line Corrosion
Common · medium severitySymptoms: transmission fluid leaking near radiator, pink fluid dripping underneath front of car, low transmission fluid level, transmission slipping or delayed engagement
Fix: Steel cooler lines rust through where they connect to radiator, especially in salt-belt states. Lines must be replaced, transmission fluid flushed and refilled. 2-3 hours labor. Check radiator for internal contamination if leak went unnoticed.
Estimated cost: $220-420
Fuel System Vapor Lock
Occasional · medium severitySymptoms: stalling in hot weather after highway driving, difficulty restarting when engine is hot, stumbling and hesitation on hot days, runs fine when cool
Fix: Fuel lines routed too close to exhaust manifold cause fuel to vaporize. Requires rerouting fuel lines away from heat sources, adding heat shields, and replacing deteriorated rubber fuel hoses. Some owners retrofit electric fuel pump. 3-4 hours labor.
Estimated cost: $280-520
Carburetor Rochester E2SE Mixture Control Solenoid Failure
Common · low severityTypical onset: 40,000-80,000 mi
Symptoms: rough idle, poor fuel economy, hesitation on acceleration, check engine light illuminated, fails emissions testing
Fix: Electronic mixture control solenoid in Rochester Dualjet carburetor fails, causing rich running condition. Solenoid replacement or carburetor rebuild required. 2-3 hours for carb rebuild. Many techs now retrofit aftermarket carbs or do Weber conversion.
Estimated cost: $320-580
Hard pass unless it's exceptionally clean, low-mileage, and cheap — engine durability issues make these a gamble even with maintenance records, and parts availability is declining.
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.