1968 PONTIAC TEMPEST

215ci I6RWDMANUALgas
5-Year Cost of Ownership
$36,222 maintenance + known platform issues
~$7,244/yr · 600¢/mile equivalent · $31,743 maintenance + $3,779 expected platform issues
Compare this engine
vs
250ci I6
vs
307ci V8
vs
350ci V8
Common Problems & Known Issues

The 1968 Tempest is a solid A-body platform with straightforward mechanicals, but after 50+ years, expect typical wear items plus some era-specific quirks around driveline mounts, automatic transmissions, and carburetion. Engine longevity depends heavily on prior maintenance and abuse.

Transmission Mount Failure and Driveline Vibration

Common · medium severity
Typical onset: 60,000+ mi or age-related deterioration
Symptoms: Clunk or thud when shifting into gear, Excessive vibration at idle or under load, Visible sagging or cracked rubber on transmission mount, Gear shifter feels loose or moves excessively
Fix: Replace transmission crossmember mount and inspect engine mounts simultaneously. Original rubber mounts deteriorate even on low-mileage cars due to age. 1.5-2 hours labor, straightforward bolt-in job.
Estimated cost: $150-300

Two-Speed Powerglide and TH400 Transmission Issues

Occasional · high severity
Typical onset: 80,000-120,000 mi or unknown service history
Symptoms: Slipping between gears or delayed engagement, No reverse or erratic shifting, Transmission fluid burnt smell or dark color, Hard shifts or banging into gear
Fix: Powerglide units are simpler but governor valve and modulator failures are common. TH400s suffer from worn clutch packs and seals. Rebuild requires 8-12 hours including R&R. If fluid service was neglected, internal damage is likely.
Estimated cost: $1,800-3,200

Carburetor Fuel Delivery and Stalling Issues

Common · medium severity
Symptoms: Hard starting when cold or hot, Stalling at idle or coming to stops, Rough idle or hesitation on acceleration, Fuel smell or evidence of leaking from carb base or fuel lines
Fix: Rochester 2-barrel carbs on I6 and small V8s need rebuild kits or replacement after sitting. Accelerator pump diaphragms, float needles, and ethanol-damaged gaskets are typical culprits. Fuel filter replacement is mandatory. Carb rebuild: 3-4 hours labor.
Estimated cost: $300-650

Worn Piston Rings and Blow-by on High-Mileage Engines

Occasional · high severity
Typical onset: 100,000-150,000 mi
Symptoms: Excessive oil consumption (1 quart per 500-1000 miles), Blue smoke on startup or deceleration, Loss of compression across multiple cylinders, Positive crankcase pressure and oil pushed out breather
Fix: Ring and piston jobs require full engine disassembly. On V8s, consider full rebuild if bearings and cylinder walls show wear. Engine removal, machine work, reassembly: 20-30 hours. Some opt for used long block swap instead.
Estimated cost: $3,500-6,500

Main and Rod Bearing Wear (326/389 V8)

Rare · high severity
Typical onset: 120,000+ mi or oil starvation history
Symptoms: Knocking or rumbling noise from bottom end, especially cold, Low oil pressure at idle, Metallic debris in oil or filter, Sudden catastrophic failure if ignored
Fix: Requires crankshaft removal, inspection, and possible machining. If crank is scored, regrind or replacement needed. Full bottom-end rebuild overlaps with ring job. 25-35 hours total if engine comes out.
Estimated cost: $4,000-7,000

Transmission Oil Cooler Line Leaks and Cooling Inadequacy

Occasional · medium severity
Symptoms: Transmission fluid spots under front of car, Rusted or corroded steel cooler lines at frame or radiator, Overheating transmission fluid on highway runs or towing, Low fluid level after no obvious pan leaks
Fix: Steel lines rot through at bends or clamps. Replace with pre-formed or custom bent lines. Add aftermarket cooler if towing or performance use. 2-3 hours labor for lines, 3-4 if adding auxiliary cooler.
Estimated cost: $250-600
Owner tips
  • Change transmission fluid and filter every 25,000-30,000 miles; the TH400 and Powerglide are bulletproof if serviced but unforgiving if neglected.
  • Use modern fuel stabilizer or non-ethanol fuel if driven infrequently; carburetors and fuel system components suffer from sitting more than miles.
  • Inspect rubber engine and trans mounts annually on cars over 10 years old—age kills these faster than mileage.
  • Run a high-zinc oil (ZDDP additive) on flat-tappet cam engines to prevent cam and lifter wear; modern oils lack the protection these engines need.
Buy one if you're comfortable with carburetor tuning and can verify the automatic trans shifts cleanly—engine parts are available and straightforward, but tired drivelines nickel-and-dime you.
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.
593 jobs across 17 categories
Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included. Built by the same team.
Try ShopBase →