1973 PONTIAC TEMPEST

350ci V8RWDAUTOMATICgas
5-Year Cost of Ownership
$14,402 maintenance + known platform issues
~$2,880/yr · 240¢/mile equivalent · $6,238 maintenance + $7,464 expected platform issues
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250ci I6
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307ci V8
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400ci V8
Common Problems & Known Issues

The 1973 Tempest represents the tail-end of the second-gen A-body platform, built during GM's emissions-choke era with detuned engines and the troublesome TH350/TH400 automatics that saw widespread fluid overheating issues. Bodies rust aggressively in the quarters and trunk floors, while drivetrain longevity heavily depends on whether the original owner maintained the cooling system religiously.

Transmission Overheating and TH350/TH400 Failure

Common · high severity
Typical onset: 60,000-90,000 mi
Symptoms: Delayed engagement into gear when cold or hot, Burnt transmission fluid smell, dark brown or black fluid, Slipping between 1-2 or 2-3 shifts under load, No reverse or erratic reverse engagement
Fix: Factory trans cooler is undersized and the routing through the radiator bottom tank cooks the fluid. Most need a full rebuild with clutch packs, bands, and seals. External auxiliary cooler is mandatory during rebuild. Expect 12-16 hours labor for R&R and rebuild, plus 2 hours for auxiliary cooler install.
Estimated cost: $1,800-2,800

Engine Bottom-End Failure (350/400/455 V8s)

Occasional · high severity
Typical onset: 80,000-130,000 mi
Symptoms: Heavy knocking from crankcase at idle that increases with RPM, Metallic debris in oil filter during changes, Oil pressure dropping below 10 psi at hot idle, Suddenly losing 15+ psi oil pressure after highway runs
Fix: Main and rod bearings fail from combination of sludge buildup (poor PCV design) and inadequate oil changes. Crank journals often need turning .010 or .020 under. Full teardown requires engine pull, hot tank, machine work, re-assembly with oversized bearings. Budget 24-32 hours labor for full rebuild including R&R.
Estimated cost: $3,200-5,500

Carburetor Base Gasket Leaks and Intake Manifold Warping

Common · medium severity
Symptoms: Rough idle that smooths out above 1500 RPM, Fuel smell in engine bay after shutdown, Visible fuel weeping around carburetor base, Vacuum leak codes if you test with propane
Fix: Rochester 2-barrel and Quadrajet carbs sit on thin gaskets that harden and leak. Intake manifolds warp from heat cycling. Requires intake removal, milling flat if warped beyond .006 inch, new gaskets and proper torque sequence. 4-6 hours labor.
Estimated cost: $450-750

Rear Quarter Panel and Trunk Floor Rust-Through

Common · medium severity
Symptoms: Bubbling paint behind rear wheels above wheel lip, Wet trunk carpet that never dries, musty smell, Visible perforation in trunk floor corners near wheelwells, Rear seat floor soft or spongy under carpet
Fix: These A-bodies trap water and road salt between inner and outer quarter panels. Trunk floors rust from inside out. Proper fix requires cutting out rust, welding patch panels or full quarters, media blasting, epoxy primer. Paintwork alone is 18-25 hours if quarters need replacement; trunk floors add 8-12 hours.
Estimated cost: $2,500-6,000

Front Subframe and Lower Control Arm Mounting Rot

Occasional · high severity
Symptoms: Clunking over bumps that sounds deep and structural, Wandering steering that feels loose in the frame, Visible rust perforation on subframe rails near radiator support, Control arm bolts that spin in their mounts
Fix: Salt-belt cars develop subframe rot where lower control arms mount. Dangerous when it lets the arm shift under braking. Requires frame section replacement or boxing/plating if caught early. Complete subframe swap is 16-22 hours; plating and welding is 10-14 hours if not too far gone.
Estimated cost: $1,400-3,200

Fuel Delivery Issues from Varnished Tank and Lines

Common · low severity
Symptoms: Stalling after 20-30 minutes of driving when tank below half, Hard starting after sitting overnight, clears after cranking, Surging at steady cruise between 45-55 mph, Fuel filter clogging every 3,000-5,000 miles
Fix: Ethanol fuel dissolves 50-year-old varnish in tank and steel lines. Sock filter in tank disintegrates and clogs inline filter repeatedly. Requires tank removal, cleaning or replacement, new sending unit, steel lines flushed or replaced with NiCopp. 6-9 hours labor.
Estimated cost: $550-950
Owner tips
  • Install an auxiliary transmission cooler immediately—the factory setup will kill the trans by 80k miles
  • Change oil every 3,000 miles with high-zinc oil (ZDDP) for flat-tappet cams; synthetic is wasted money here
  • Inspect subframe and floor pans with a screwdriver every spring—surface rust hides structural rot underneath
  • Replace rubber fuel lines every 5 years; age kills them faster than mileage on these vintage systems
Buy only if rust-free with documented trans cooler upgrade and recent fluid services; budget $3k-5k for deferred maintenance on any 'barn find' example.
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.
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