2004 LEXUS IS 300

Typical onset: 80,000-150,000 mi

Symptoms: Pink or milky transmission fluid, Transmission slipping or delayed engagement, Coolant in transmission pan, Engine overheating in some cases

Fix: The factory internal cooler in the radiator fails, allowing coolant and ATF to mix. Requires radiator replacement, external cooler addition, complete fluid flush of both systems, and often transmission replacement if contamination went unnoticed. 6-10 hours labor depending on transmission damage.

Estimated cost: $1,200-$4,500

Typical onset: 90,000-140,000 mi

Symptoms: Clunking on acceleration or deceleration, Excessive drivetrain movement felt through shifter, Vibration at idle in Drive, Harsh shifts

Fix: Rubber mounts deteriorate from heat and age. Rear transmission mount is the usual culprit. Replacement is straightforward with transmission support. 1.5-2.5 hours labor.

Estimated cost: $250-$450

Typical onset: 180,000-250,000 mi

Symptoms: Blue smoke on startup or deceleration, Oil consumption over 1 quart per 1,000 miles, Rod knock or main bearing noise, Low compression on multiple cylinders

Fix: The 2JZ-GE is durable but not invincible. Neglected oil changes or extended high-mileage use leads to ring wear and bearing degradation. Full rebuild requires head gasket set, all rings, bearings, and machine work. 25-35 hours labor. Short block replacement is 20-28 hours if core is available.

Estimated cost: $4,500-$7,500

Typical onset: 120,000-180,000 mi

Symptoms: Hesitation or stumble under load, Intermittent stalling, Hard starting after sitting, Fuel pump whine

Fix: The IS 300 uses an in-tank filter integrated with the pump assembly. Often overlooked in maintenance. Requires fuel tank drop and pump assembly replacement. 3-4 hours labor.

Estimated cost: $600-$950

Typical onset: 100,000-150,000 mi

Symptoms: Clunking over bumps, Steering wander or looseness, Uneven tire wear on inside edge, Play visible during suspension inspection

Fix: Front lower ball joints wear from normal use and cannot be serviced separately—requires full lower control arm replacement on each side. 2.5-3.5 hours labor for both sides with alignment.

Estimated cost: $700-$1,100

Typical onset: 130,000-180,000 mi

Symptoms: Grinding or whining noise from belt area, Battery warning light, Dimming lights or electrical issues, Belt squeal that doesn't resolve with tensioner adjustment

Fix: Original Denso alternators develop bearing noise before electrical failure. Rebuild kits exist but replacement is more reliable. Serpentine belt should be replaced simultaneously. 1.5-2 hours labor.

Estimated cost: $450-$750

Typical onset: 110,000-160,000 mi

Symptoms: Whining noise during turns, especially when cold, Fluid leak from pump or high-pressure line, Heavy steering effort intermittently, Fluid level drops repeatedly

Fix: Pump seals age out and high-pressure lines crack at crimp points. Pump replacement or rebuild with new lines and fluid flush. 2-3 hours labor.

Estimated cost: $500-$850