1970 PONTIAC GTO

Typical onset: 80,000-120,000 mi or unknown history

Symptoms: Slipping between gears especially 1-2 shift under load, Delayed engagement when shifting into drive or reverse, Burnt transmission fluid smell and dark/burnt fluid appearance, Overheating on highway drives without auxiliary cooler

Fix: Full rebuild with clutch packs, bands, seals, and bushings is standard. Most survivors need the cooler lines and radiator-mounted cooler inspected or replaced. External auxiliary cooler highly recommended. Figure 12-16 hours labor for removal, rebuild, and reinstall.

Estimated cost: $2,200-3,800

Typical onset: 100,000+ mi or abuse history

Symptoms: Deep knocking or rattling at idle that increases with RPM, Low oil pressure at operating temperature (under 20 psi hot idle), Metallic debris in oil filter or pan during changes, Sudden catastrophic noise followed by seized engine

Fix: Requires engine removal and complete disassembly. Main and rod bearings replaced, crank checked for out-of-round and polished or turned if needed. Often becomes a full rebuild when you're that deep. Count on 25-35 hours for R&R and machine work turnaround time.

Estimated cost: $4,500-7,500

Typical onset: 90,000-150,000 mi

Symptoms: Excessive blue smoke on startup and during acceleration, High oil consumption - quart every 500-800 miles, Poor compression readings across multiple cylinders, Blowby visible at PCV valve or oil filler cap

Fix: Requires cylinder honing or boring if tapered, new pistons or rings depending on bore condition, and full top-end gasket set. Engine out for proper work. 20-30 hours including removal. Often escalates to full rebuild when cam and lifters are inspected.

Estimated cost: $3,500-6,000

Symptoms: Hard starting when cold or heat-soaked, Rough idle, hunting, or stalling at stop lights, Hesitation or flat spot during acceleration, Fuel leaking from throttle shafts or bowl gaskets

Fix: Full rebuild kit with gaskets, needle/seat, accelerator pump, and float adjustment usually required. Throttle shaft bushings if worn. Proper tuning after rebuild takes 1-2 hours. Total 3-5 hours for experienced carb tech.

Estimated cost: $450-850

Symptoms: Misfiring or stumbling under load, Difficult starting especially when hot, Loss of power at higher RPM, Points burning or pitting rapidly

Fix: Distributor bushings wear causing timing scatter. Rebuild distributor with new bushings, points, condenser, cap, rotor. Many owners convert to electronic ignition (Pertronix or HEI swap) for reliability. 2-4 hours labor depending on route.

Estimated cost: $300-650

Symptoms: Visible rust perforation in frame rails especially rear sections, Body flex or creaking over bumps, Doors misaligned or hard to close, Sagging body at mount points

Fix: Frame rust is structural and safety-critical. Minor surface rust can be treated, but perforation requires sectioning and welding new steel. Body mounts are rubber-bonded and all typically need replacement by now. 8-12 hours labor for mounts, frame repairs vary wildly by severity.

Estimated cost: $800-1,500 for mounts; frame repairs $2,000-8,000+

Symptoms: Intermittent fuel starvation or cutting out under acceleration, Clogged fuel filter repeatedly, Fuel pump clicking or struggling, Visible rust or sediment in fuel filter

Fix: Old tanks accumulate rust and varnish. Tank needs removal, cleaning or replacement, new sending unit, fuel lines inspected. Mechanical fuel pump replacement common. 4-6 hours labor for complete fuel system service.

Estimated cost: $600-1,200