1999 PLYMOUTH NEON

Typical onset: 60,000-100,000 mi

Symptoms: White smoke from exhaust, Overheating without external leaks, Coolant loss with no visible puddles, Milky oil or oil in coolant reservoir, Rough idle and misfires

Fix: Head gasket replacement on the 2.0L SOHC requires 6-8 hours labor. Head must be checked for warping and resurfaced in most cases (add 2-3 hours and machine shop fees). Timing belt, water pump, and coolant should be done simultaneously since you're already in there. Many shops recommend replacing the head outright if mileage is over 120k.

Estimated cost: $1,200-2,200

Typical onset: 80,000-130,000 mi

Symptoms: Harsh or delayed shifting, Slipping between gears especially 2nd to 3rd, No movement in drive or reverse, Burnt transmission fluid smell, Check engine light with transmission codes

Fix: The 3-speed automatic is notoriously weak in these cars. Rebuilds rarely last — most techs recommend a used low-mileage replacement (4-6 hours labor) or an upgraded unit. Transmission cooler lines and the external cooler often corrode and leak, which accelerates internal damage. If caught early, a cooler line replacement runs 1-2 hours.

Estimated cost: $1,800-3,200

Typical onset: 120,000-180,000 mi

Symptoms: Heavy knocking noise from bottom end especially on cold start, Low oil pressure warning, Metallic rattling that worsens with RPM, Metal shavings in oil during changes

Fix: This is a bottom-end failure requiring either a short block replacement or full engine rebuild. Short block swap takes 12-16 hours labor. Often paired with head work if the engine overheated previously. At this point, most owners total the car or swap in a junkyard engine (8-10 hours).

Estimated cost: $2,500-4,500

Typical onset: 70,000-120,000 mi

Symptoms: Severe clunking when shifting into drive or reverse, Vibration through the floor and shifter, Engine rocks excessively during acceleration, Visible sagging or torn rubber on mount

Fix: The front and rear transmission mounts wear quickly, especially on automatics. Front mount replacement is 1.5-2 hours, rear mount about 1 hour. Replace both at the same time. Cheap parts, straightforward job, makes a huge difference in NVH.

Estimated cost: $250-450

Typical onset: 100,000-150,000 mi

Symptoms: Burning 1+ quart of oil every 500-800 miles, Blue smoke on startup or acceleration, Fouled spark plugs, Loss of power and rough running

Fix: High-mileage 2.0L engines develop piston ring wear and cylinder scoring. A proper fix requires an engine rebuild with new pistons, rings, and honing or boring (20+ hours labor). Most opt for a used engine swap instead. Band-aid fix: heavier oil and frequent top-offs, but compression loss will worsen.

Estimated cost: $2,000-3,500

Symptoms: Hard starting especially when warm, Sputtering and stalling under load, Loss of power on hills or highway merging, Check engine light with lean codes

Fix: The in-tank fuel filter (part of the pump assembly) clogs with sediment over time, and there's no serviceable inline filter. Requires dropping the tank and replacing the entire pump module (2-3 hours labor). Cheap insurance to do this preventively on any unknown-history Neon.

Estimated cost: $300-550