The 1973 Coronet is a solid B-body Mopar with typical Chrysler slant-six and LA/B-block V8 reliability, but suffers from dated emission controls, aging fuel system components, and rust issues common to early-70s Mopars. Most mechanical problems are straightforward fixes for anyone comfortable with carbureted engines.
Timing Chain Stretch and Wear (V8 engines)
Common · medium severityTypical onset: 80,000-120,000 mi
Symptoms: Rough idle and hesitation on acceleration, Rattling noise from timing cover at startup, Difficulty starting when hot, Check timing and it's retarded 5-10 degrees from spec
Fix: Replace timing chain, gears, and cam button. With the radiator and balancer off, it's 4-6 hours for a competent tech. Most shops do the full timing set while they're in there. Original nylon-toothed cam gears are often the culprit—they shed teeth.
Estimated cost: $400-750
Carburetor Issues (All engines)
Common · medium severitySymptoms: Hard starting, especially when cold, Stalling at idle or when coming to a stop, Black smoke and fuel smell from rich running, Surging or flat spots during acceleration
Fix: These Carter BBD and Holley 2-barrels don't age well—accelerator pump diaphragms crack, float needles stick, and emission-control vacuum lines rot. Rebuild kits run $40-80, labor is 2-3 hours if you clean and reset everything properly. Often cheaper to swap for an aftermarket Edelbrock.
Estimated cost: $200-500
Torsion Bar Anchor Corrosion and Suspension Sag
Common · medium severityTypical onset: any—age and rust-belt exposure matter more
Symptoms: Front end sits low, uneven ride height side-to-side, Clunking over bumps from loose torsion bar hex, Visible rust scaling around lower control arm pivot and K-frame, Alignment won't hold, car wanders
Fix: Torsion bar adjusters seize or the hex sockets in the LCA rust out. If just seized, penetrant and heat plus adjustment gets you back. If the K-frame or LCA is rotted, you're looking at fabrication or replacements. Budget 3-5 hours labor for torsion bar service and alignment, more if welding frame patches.
Estimated cost: $300-1,200
Fuel System Deterioration (Tank, Lines, Pump)
Occasional · high severitySymptoms: Fuel smell inside or outside the car, Stalling after 15-20 minutes of driving as mechanical pump gets hot, Visible rust flakes in fuel filter, Leak stains on tank or along frame rails
Fix: 50-year-old fuel tanks rust from inside out, rubber hoses crack, and steel lines corrode at the frame. Mechanical fuel pumps also fail from worn diaphragms. Tank replacement is 4-5 hours, pump is 1 hour. Do it all at once if the tank's sketchy—you don't want a fuel leak or roadside failure.
Estimated cost: $600-1,400
Floor and Frame Rail Rust (Rust Belt cars)
Common · high severitySymptoms: Visible holes in front floor pans and rear torque box areas, Soft or flaky metal under carpet, Cracking paint and bubbling on rocker panels, Rear leaf spring mounts show surface rust or separation
Fix: B-bodies rust in predictable spots: front floor pans, rear torque boxes, lower quarters behind wheel wells, and frame rails at the rear spring hangers. Minor surface rust is DIY-manageable, but structural rust needs patch panels and welding. Labor varies wildly—figure 10-20+ hours for proper floor pan replacement.
Estimated cost: $1,500-5,000
Cooling System Leaks and Overheating (V8 models)
Occasional · medium severityTypical onset: any—age-related
Symptoms: Temperature gauge creeps into hot range in traffic or on hills, Coolant puddles under car after shutdown, Heater performance drops, White residue around water pump weep hole or intake manifold corners
Fix: Original radiators are often partially clogged or have leaking seams, water pumps weep from worn bearings, and intake manifold gaskets leak coolant into the valley. Water pump is 2 hours, radiator is 3-4 if you pull the shroud and fan properly. If doing intake gaskets (common on 318/360), add 5-6 hours.
Estimated cost: $350-1,100
Worn Steering Box and Linkage
Common · low severityTypical onset: 70,000+ mi
Symptoms: Excessive play in steering wheel—1-2 inches of slop before wheels respond, Wandering on highway, constant correction needed, Clunking when hitting bumps or changing direction
Fix: Manual steering boxes wear at the sector shaft, and the centerlink/tie rod ends develop slop. Rebuild or replace the steering box (3-4 hours), and plan on all new tie rod ends and idler arm. Aftermarket boxes are cheap but quality varies. Alignment required after.
Estimated cost: $400-800
Buy one if the body is solid and you're comfortable with carbs and points—mechanicals are simple and parts are cheap, but rust and neglected fuel systems will eat your budget.
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.