2010–2015 Toyota Prius: Coolant loss, misfire or head gasket failure (EGR clogging)
Likely causes, ranked
- Head gasket failure$1,500–$3,500Shop
- Clogged EGR cooler/intake passages (cleaning)$250–$450Shop
Real-owner fix counts will appear here as reports come in.
Rough cost: $250–$3,500DIY or shop: See DIY or shop section
Parts to check
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Symptom: Coolant slowly disappearing, a misfire or rough start (especially cold), and white smoke.
Likely causes
- Head gasket. PriusChat owners report gen-3 head gasket failures at higher mileage.
- EGR system. Many link clogged EGR passages to the failures and clean the EGR system preventively.
Rough cost range
| Repair | Reported |
|---|---|
| Head gasket, independent hybrid shop | About $1,500–$3,500 (Tucson Hybrids) |
| EGR cleaning | About $250–$450 |
DIY or shop?
Shop, although EGR cleaning is DIY-capable.
Useful steps
- Watch the coolant level.
- Consider EGR cleaning at high mileage.
- Get the head checked for warping.
Vehicle focus: 2010–2015 Toyota Prius.
Safety / mechanic note
Overheating can destroy the engine. Verify with a mechanic.
Related trouble codes
Recalls & service bulletins
No recalls or service bulletins are listed for this page yet.
NHTSA complaints: 115 keyword-matched complaints (of 4,840 unique complaints filed under NHTSA model names PRIUS, 2010–2015; NHTSA complaints API by model year, queried 2026-10-15).
Always check your VIN for open recalls at nhtsa.gov/recalls.
Sources
What actually fixed it?
Had this problem? Tell other owners what the real fix was. Reports are counted above; we never show made-up numbers.