The 2007 Scion tC with the 2AZ-FE 2.4L I4 is a generally reliable sporty compact, but has a devastating Achilles heel: excessive oil consumption leading to catastrophic engine failure, particularly in early-production engines. When maintained religiously and monitored for oil level, these cars can reach high mileage, but the engine risk looms large.
Excessive Oil Consumption / Piston Ring Failure (2AZ-FE Engine)
Common · high severityTypical onset: 60,000-120,000 mi
Symptoms: Burning 1+ quart of oil every 1,000 miles without visible external leaks, Blue smoke from exhaust on startup or acceleration, Sudden engine seizure if oil level drops too low unnoticed, Check engine light with lean codes (P0171/P0174) from oil fouling O2 sensors
Fix: Toyota issued TSB and extended warranty for some VINs, but many 2007s fall outside coverage. Proper fix requires engine rebuild with updated pistons and rings (18-22 labor hours) or short block replacement (20-24 hours). Some owners limp along adding oil constantly, but seizure risk is real.
Estimated cost: $3,500-5,500
Transmission Oil Cooler Line Failure
Occasional · medium severityTypical onset: 80,000-140,000 mi
Symptoms: Transmission fluid dripping or pooling under vehicle, usually passenger side, Burnt transmission fluid smell after highway driving, Delayed or harsh shifting as fluid level drops, Pink or red fluid visible on driveway
Fix: Steel cooler lines corrode where they connect to radiator or run along subframe. Replace both lines preventively (2.5-3.5 hours), flush transmission fluid, inspect radiator end-tanks for cross-contamination if failure was severe.
Estimated cost: $400-700
Front Engine Mount (Torque Mount) Failure
Common · low severityTypical onset: 70,000-110,000 mi
Symptoms: Clunking or thudding when shifting from Park to Drive or Reverse, Excessive engine movement visible from engine bay during acceleration, Vibration through cabin at idle, especially with A/C on, Transmission shifter vibrates abnormally
Fix: Hydraulic front mount separates internally. Replacement is straightforward but requires supporting engine from above or below (1.5-2.0 hours). OEM or quality aftermarket recommended—cheap mounts fail quickly.
Estimated cost: $250-400
Camshaft Position Sensor Failure
Occasional · medium severityTypical onset: 90,000-150,000 mi
Symptoms: No-start or extended cranking, especially when engine is hot, Check engine light with P0340 or P0345 codes, Intermittent stalling at idle or during deceleration, Rough idle or hesitation that comes and goes
Fix: Sensors on valve cover fail from heat cycling. Both intake and exhaust sensors should be replaced together (1.0-1.5 hours). Use OEM Denso sensors—aftermarket sensors often fail prematurely on this engine.
Estimated cost: $300-500
EVAP Canister Vent Valve Sticking
Occasional · low severitySymptoms: Check engine light with P0441, P0446, or P0455 codes, Fuel tank difficult to fill—pump clicks off repeatedly, Slight fuel smell near rear of vehicle, EVAP system fails emissions test
Fix: Charcoal canister vent valve (VSV) sticks open or closed. Located near fuel tank, accessible from underneath (0.8-1.2 hours). Sometimes just the valve, sometimes whole canister if saturated from topping off tank repeatedly.
Estimated cost: $200-450
Lower Control Arm Bushings Deterioration
Common · low severityTypical onset: 80,000-130,000 mi
Symptoms: Clunking over bumps from front suspension, Steering wheel off-center after alignment, or alignment won't hold, Uneven inner tire wear, Wandering or vague steering feel
Fix: Rear bushings in lower control arms crack and separate. Most shops replace entire arms rather than press bushings (2.5-3.5 hours both sides). Alignment mandatory after replacement.
Estimated cost: $500-800
Buy only if oil consumption history is documented as normal and price reflects engine-rebuild risk; otherwise, the $4,000 bomb waiting under the hood makes this a gamble.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.