1990 MITSUBISHI GTO

Typical onset: 80,000-150,000 mi

Symptoms: Loud ticking or tapping from valve covers at startup, may persist after warmup, Misfires or rough idle if lifter completely collapses, Check engine light with cylinder misfire codes

Fix: Replace all lifters as a set—never do singles. Requires removing intake plenum, fuel rails, and both valve covers. Budget 8-12 hours labor due to engine bay congestion. On turbo models, add time for intercooler pipe removal. Always replace cam seals and valve cover gaskets while you're in there.

Estimated cost: $1,200-2,200

Typical onset: 60,000-90,000 mi intervals

Symptoms: No symptoms until catastrophic failure—this is interference engine territory, Coolant weeping from water pump before belt failure, Squealing from worn belt tensioner bearings

Fix: This is a 12-16 hour job on the GTO due to removing the entire front accessory stack, motor mounts, and jacking the engine. Timing belt, tensioner, water pump, cam and crank seals are mandatory. Turbo models require additional intercooler and piping removal. If this snaps, you're looking at valve-to-piston contact and a full head rebuild or engine replacement.

Estimated cost: $1,800-3,000

Typical onset: 70,000-120,000 mi

Symptoms: Clunking or excessive drivetrain movement during shifts or acceleration, ATF puddles under the rear of the transmission, Transmission overheating or slipping if cooler fails completely

Fix: Transmission mounts collapse from age and heat—replacing them requires supporting the transmission and takes 3-4 hours. The rear transmission oil cooler, a GTO-specific feature, develops leaks at hard lines and seals. Cooler replacement is 4-6 hours because it's buried under exhaust and driveshaft components. Do both together if you're already under there.

Estimated cost: $800-1,500

Typical onset: 90,000-140,000 mi

Symptoms: White smoke from exhaust, especially at cold start, Coolant consumption with no visible external leaks, Overheating, bubbling coolant reservoir, or pressurized cooling system, Milky oil on dipstick or oil cap in severe cases

Fix: Single head gasket jobs are 14-18 hours due to removing turbos, exhaust manifolds, intake plenum, and all accessory plumbing. Most shops recommend doing both heads simultaneously—add another 6-8 hours. Always resurface heads and replace head bolts. If you're in this deep, do the timing belt, water pump, and cam seals at the same time or you'll regret it within a year.

Estimated cost: $3,500-6,000

Typical onset: Any mileage—age and disuse are the enemy

Symptoms: Rear spoiler won't deploy or retract, grinding noises from trunk, 4WS warning light, rear wheels don't respond to steering input, Pop-up headlights stuck open or closed

Fix: The active aero motor and cables seize from corrosion—replacement motors are NLA, so expect junkyard hunting or manual conversion (2-3 hours). The 4WS system uses a rear steering rack that fails electronically or mechanically; repair parts are scarce and a used rack swap runs 6-8 hours. Many owners delete 4WS entirely and install a solid rear subframe bushing.

Estimated cost: $500-1,800

Typical onset: 100,000-150,000 mi

Symptoms: Rattling noise at idle from engine bay—wastegate actuator rods wear out, Blue smoke on deceleration or at startup indicates turbo seals failing, Loss of boost pressure, sluggish acceleration, or overboost codes

Fix: Wastegate rattle can be fixed with upgraded actuator rods or rebuilt turbos. Full turbo replacement requires 10-14 hours—you're removing the entire upper intake, intercooler piping, exhaust manifolds, and oil/coolant lines. OEM turbos are discontinued; expect rebuild or aftermarket. Many owners upgrade to modern ball-bearing turbos at this point.

Estimated cost: $2,000-4,500