1980 CADILLAC DEVILLE

Typical onset: 60,000-100,000 mi

Symptoms: white smoke from exhaust, coolant consumption with no external leaks, loss of power, hard starting when warm, metal shavings in oil

Fix: Oldsmobile 350 diesel has chronic head gasket failures due to inadequate head bolt design and block cracking from water jacket casting flaws. Repair requires full engine removal, block inspection, head resurfacing, ARP studs, and often complete rebuild or replacement with gas engine swap. 25-35 hours labor for rebuild, 15-20 for swap if parts are ready.

Estimated cost: $3,500-6,500

Typical onset: 80,000-150,000 mi

Symptoms: transmission fluid dripping from front of car, pink fluid puddles, transmission slipping after leaks develop, overheating on highway

Fix: Steel cooler lines rust through at crimped fittings and radiator connection points. Replacement requires new pre-bent lines or custom fabrication. While lines are off, flush cooler and check radiator for internal cross-contamination. 2-3 hours labor.

Estimated cost: $300-550

Typical onset: 100,000-140,000 mi

Symptoms: ticking or tapping from valve covers, loss of power, rough idle, oil consumption, check engine light (if equipped)

Fix: Factory rocker arms and worn valve guides cause excessive oil consumption and noise. Complete valve job includes guide replacement, valve grinding, new rockers, lifters inspection, and timing chain while you're in there. 12-16 hours labor.

Estimated cost: $1,800-2,800

Typical onset: 70,000-120,000 mi

Symptoms: clunk when shifting from park to drive, excessive vibration at idle in gear, visible sag of transmission tail, driveline shudder on acceleration

Fix: Rubber mount deteriorates and transmission tail drops, causing driveline angle problems and U-joint wear. Requires lift, transmission support, and mount replacement. Check crossmember for rust while there. 1.5-2 hours labor.

Estimated cost: $200-350

Symptoms: hard starting after sitting, rough idle and stalling, hesitation on acceleration, black smoke, fuel smell

Fix: Rochester Quadrajet carburetors accumulate varnish from ethanol fuel, especially in cars that sit. Requires removal, complete rebuild with kit, float adjustment, and proper tuning. Fuel filter often overlooked and causes repeat issues. 4-6 hours for proper rebuild and tune.

Estimated cost: $450-750

Typical onset: 90,000-130,000 mi

Symptoms: overheating in traffic, coolant leaks from radiator seams, rusty coolant, heater not working properly, transmission overheating

Fix: Original brass radiators corrode internally, especially if Dex-Cool was added later. Replacement with aluminum or quality brass unit, new hoses, thermostat, and complete flush. Check heater core at same time. 3-4 hours labor.

Estimated cost: $500-900

Typical onset: 80,000-140,000 mi

Symptoms: wandering at highway speed, clunking over bumps, uneven tire wear, loose steering feel, bottoming out easily

Fix: Ball joints, control arm bushings, and shocks wear together. Complete front end rebuild with alignment recommended over piecemeal repairs on these heavy cars. Idler arm and center link often overlooked. 6-8 hours for complete job.

Estimated cost: $1,200-1,800