1998 PLYMOUTH NEON

Typical onset: 60,000-120,000 mi

Symptoms: White smoke from exhaust, especially on cold starts, Coolant loss with no visible leaks, milky oil on dipstick, Overheating even after thermostat/radiator replacement, Rough idle, misfire codes, loss of compression on cylinders 2 and 3

Fix: Head gasket job requires 8-10 hours labor, but if coolant contaminated the oil and the engine overheated, you're often looking at machining the head ($150-250) or full engine rebuild with pistons, rings, bearings. Many techs find scored cylinder walls or cracked heads once they're in there. This is the Neon's Achilles heel — the 2.0L SOHC uses a marginal multi-layer steel gasket that fails between cylinders 2-3, and owners who ignore early symptoms end up needing complete short blocks.

Estimated cost: $1,200-3,500

Typical onset: 80,000-140,000 mi

Symptoms: Slipping between gears, especially 2nd to 3rd, Delayed engagement when shifting into Drive or Reverse, Burnt transmission fluid smell, dark or metallic fluid, Complete loss of forward gears, stuck in limp mode

Fix: The 31TH 3-speed auto is notoriously weak, with solenoid pack and clutch pack failures. Rebuild runs 12-16 hours labor plus $800-1,200 in hard parts. Used transmissions are plentiful but often just as worn. The transmission oil cooler (built into the radiator) also leaks internally, mixing coolant and ATF, which destroys the trans within days if not caught. Always check for strawberry-milkshake fluid color.

Estimated cost: $1,800-2,800

Typical onset: 70,000-130,000 mi

Symptoms: Intermittent no-start, cranks but won't fire, Stalling at idle or while driving, then restarts after cooling, Check engine light with P0320 or P0335 codes, Tachometer drops to zero while driving

Fix: The crank sensor mounts on the bell housing behind the engine, accessible from underneath. It's heat-sensitive and fails when hot, then works again when cool, making diagnosis tricky. Replacement is 1.0-1.5 hours labor, sensor costs $40-80. Sometimes the cam sensor also fails (similar symptoms), so diagnose carefully before throwing parts.

Estimated cost: $120-220

Typical onset: 80,000-150,000 mi

Symptoms: Excessive vibration at idle, especially with A/C on, Clunking when shifting from Park to Drive or Reverse, Engine visibly rocks side-to-side during acceleration, Shifter vibration, hard shifts in automatic models

Fix: Neons eat motor mounts — the front engine mount and right-side transmission mount are hydraulic and fail frequently. The transmission mount is the worst offender, allowing the trans to sag and stress the cooler lines. Replace both mounts (2.5-3.5 hours labor total). Use OE or quality aftermarket; cheap mounts fail in 20,000 miles.

Estimated cost: $300-500

Typical onset: 90,000-120,000 mi

Symptoms: Squealing or grinding noise from timing belt area, Coolant leak from weep hole below timing cover, Engine overheating due to water pump failure, Sudden catastrophic engine damage if belt fails

Fix: This is an interference engine — if the timing belt breaks, valves meet pistons and you're rebuilding. The water pump is driven by the timing belt and often leaks around 100k. Timing belt service is 3.5-4.5 hours labor; always include tensioner, idler pulley, and water pump in the kit. If you're doing head gaskets, the timing belt is right there — do it then.

Estimated cost: $500-750

Typical onset: 100,000-150,000 mi

Symptoms: Coolant puddles under car, usually passenger side, Overheating in traffic or on highway, Plastic radiator end tanks cracked or split, Heater core leaking coolant onto passenger floor

Fix: The radiator uses plastic end tanks that crack with age and heat cycling. Radiator replacement is 2-3 hours labor. The integrated transmission cooler failure (mentioned earlier) is a separate but related disaster. Heater core replacement requires full dash removal — 8-10 hours labor — so many owners just bypass it if the leak is small.

Estimated cost: $250-450 (radiator), $600-900 (heater core)

Symptoms: Intermittent stalling, no-start with multiple codes, Gauges acting erratically, speedometer drops out, Random misfires, fuel trim codes, Battery drain, no communication with scanner

Fix: The PCM is mounted low on the firewall and vulnerable to water intrusion from clogged cowl drains or sunroof leaks. Corrosion on the main engine harness connectors (behind the battery and near the PCM) causes bizarre issues. Diagnosis is time-consuming (2-4 hours), PCM replacement/reflash is $300-600, harness repair varies widely. Check grounds at the strut towers and battery tray for corrosion.

Estimated cost: $200-800