1982 PONTIAC GRAND PRIX

Typical onset: 60,000-90,000 mi

Symptoms: Slipping between 1st and 2nd gear under load, No reverse or intermittent reverse engagement, Delayed engagement when shifting into drive, Metal shavings in transmission pan during fluid change

Fix: The THM200 and its overdrive sibling are notoriously weak, especially behind the V8s. Rebuild typically takes 8-12 hours at a competent shop; many techs recommend upgrading to a THM350 swap instead for long-term reliability, which adds 4-6 hours but eliminates repeat failures. Transmission cooler lines and radiator cooler often need replacement simultaneously.

Estimated cost: $1,800-3,200

Typical onset: 50,000-120,000 mi

Symptoms: Hard starting when cold, requires multiple cranking cycles, Hesitation or stumble during acceleration, Black smoke from exhaust under load, Stalling at idle or when coming to a stop, Fuel smell in cabin or engine bay from leaking accelerator pump

Fix: The Rochester Quadrajet needs periodic rebuilds due to worn needle-and-seat assemblies, deteriorated float, and failed accelerator pump seals. A proper rebuild takes 3-4 hours including removal, disassembly, cleaning, new kit installation, and on-car tuning. Many owners retrofit an Edelbrock or Holley instead (5-6 hours with tuning) to eliminate chronic Q-jet problems.

Estimated cost: $400-900

Typical onset: 70,000-110,000 mi

Symptoms: Oil puddle under rear of engine after sitting overnight, Oil coating on flywheel/flexplate visible through bellhousing inspection cover, Burning oil smell when idling after highway driving, Gradual oil level drop between changes

Fix: GM's two-piece rear main seal from this era is prone to leaking, particularly on engines with worn crankshafts. Repair requires transmission removal — 10-14 hours labor depending on engine/trans combo. Many techs also replace the oil pan gasket and valve cover gaskets while in there since oil leaks tend to cluster.

Estimated cost: $800-1,500

Typical onset: 80,000-130,000 mi

Symptoms: Coolant level drops with no visible external leaks, White smoke from exhaust on cold start that clears up, Rough idle and possible misfire after sitting, Coolant in oil (milky dipstick) in severe cases

Fix: The intake manifold gaskets deteriorate and allow coolant into the intake ports or crankcase. Repair involves pulling the intake, cleaning mating surfaces, replacing gaskets, and torquing to spec in proper sequence. Takes 4-6 hours. On the 231 V6 and 301/305 V8, it's smart to replace the distributor o-ring and thermostat housing gasket at the same time.

Estimated cost: $600-1,100

Symptoms: Check engine light illuminated constantly, Poor fuel economy (dropping below 12 mpg city), Engine runs but won't pass emissions testing, Erratic idle speed or stalling in closed-loop mode

Fix: The early CCC electronics are primitive and prone to failing oxygen sensors, ECM issues, and corroded wiring harnesses. Diagnosis takes 1-2 hours with a scanner or manual code retrieval. Common culprits: O2 sensor ($80-150 plus 0.5 hours), throttle position sensor ($60-120 plus 1 hour), or ECM itself ($200-400 plus 1.5 hours to reprogram/replace).

Estimated cost: $200-800

Typical onset: 60,000-100,000 mi

Symptoms: Clunking noise over bumps from front suspension, Wandering or loose steering feel at highway speed, Uneven tire wear on inside or outside edges, Visible play when prying on tire with vehicle jacked up

Fix: GM A-body front suspension ball joints wear out and can separate catastrophically. Both uppers and lowers should be replaced together — 4-6 hours per side for a quality job including alignment afterward. Upper ball joints are riveted from factory and must be drilled out.

Estimated cost: $600-1,200

Typical onset: 80,000+ mi

Symptoms: Squeaks and rattles from body-to-frame interface over bumps, Doors misaligned or difficult to close properly, Visible gaps between body and frame at mount points, Cracked or missing rubber body mount bushings

Fix: The rubber body mounts dry-rot and collapse over time, especially in rust-belt cars. Replacement requires lifting the body off the frame at each mount point — 6-10 hours depending on rust and seized hardware. Often discover frame rust during this job that complicates things.

Estimated cost: $500-1,000