1990 FORD AEROSTAR

Typical onset: 80,000-140,000 mi

Symptoms: White smoke from exhaust, particularly on cold starts, Coolant loss with no visible leaks, Milky oil on dipstick or oil cap, Overheating under load or in traffic

Fix: Both cylinder heads off, resurface mandatory due to warping tendency. Expect 12-16 labor hours for the job. 4.0L is slightly worse because exhaust manifolds are prone to breaking studs. Replace timing cover gasket, valve cover gaskets, and intake manifold gaskets while you're in there or you'll be back in six months.

Estimated cost: $1,800-3,200

Typical onset: 90,000-130,000 mi

Symptoms: Harsh 1-2 shift or no 2nd gear engagement, Slipping on acceleration, especially with load, Brown or burnt-smelling transmission fluid, No movement in drive or reverse (complete failure)

Fix: The A4LD behind the 3.0L is notoriously weak. Throttle valve cable adjustment helps longevity but most need a rebuild or replacement by 120k. Cooler lines rust through and contaminate fluid. Budget 10-14 hours for R&R plus rebuild. Aftermarket reman units are hit-or-miss; find a reputable local transmission shop.

Estimated cost: $1,600-2,800

Symptoms: Fuel smell under vehicle, particularly after fillup, Visible rust perforation on top of tank, Fuel gauge reading empty when tank is full, or stuck at one position, Fuel puddles after parking on incline

Fix: Aerostar tanks rust from the top down due to road salt and moisture trapped by the straps. Recall addressed some early corrosion but many tanks are now 30+ years old. Tank replacement requires dropping the entire assembly, 3-4 hours labor. Sender units fail separately from corrosion on the rheostat. Replace both together.

Estimated cost: $600-1,100

Typical onset: 100,000-150,000 mi

Symptoms: Severe vibration at idle that worsens with RPM, Serpentine belt throwing or shredding repeatedly, Visible wobble of balancer pulley when engine running, Rubber ring between hub and outer ring visibly deteriorated

Fix: The rubber damper ring delaminates with age and heat cycles. When it lets go, the outer pulley wobbles and can take out the front main seal or destroy accessory belts. Replacement is 2-3 hours with the right puller tool. Do NOT drive it once you see wobble — catastrophic timing chain damage is possible if the balancer comes completely apart.

Estimated cost: $400-700

Symptoms: No-start when engine is hot, starts fine when cold, Stalling at idle after 20+ minutes of driving, Intermittent stumble or misfire under load, Dies and won't restart until engine cools for 30+ minutes

Fix: Ford's Thick Film Ignition module mounts on the distributor and overheats. Classic failure mode is hot no-start. Distributor bushings wear causing timing wander. Replace TFI module first ($50 part, 0.5 hours), but if distributor shaft has play, replace the whole unit. Aftermarket modules from discount chains fail constantly; use Motorcraft.

Estimated cost: $150-500

Typical onset: 60,000-100,000 mi

Symptoms: Steering wheel pulsation during braking, Vehicle pulls to one side under moderate braking, One front wheel noticeably hotter than the other after driving, Brake pedal sinks slowly to floor when stopped at light

Fix: The front discs are undersized for the vehicle weight and warp easily if overtorqued or overheated. Caliper slide pins seize from lack of lubrication. Resurface rotors if under minimum thickness, but replacement is often cheaper. Master cylinder recall was issued but seals still fail over time. Budget 2-3 hours for full front brake job with caliper service.

Estimated cost: $400-800

Typical onset: 90,000+ mi

Symptoms: Oil spots on driveway directly under front of engine, Oil coating visible on lower engine block and crossmember, Oil level drops 1 quart between changes with no visible drips, Burning oil smell after highway driving

Fix: Cork-rubber gaskets harden and leak over time. Timing cover leaks are 4-6 hours because you must remove harmonic balancer, water pump, and accessories. Oil pan requires removing crossmember on 2WD, more labor on AWD. Not urgent but annoying and makes it hard to spot fresh leaks from more serious problems like rear main seal.

Estimated cost: $500-1,200