It started with shaking on startup, idle and low speeds. Check engine light came on. Diagnosed with multiple cylinder misfire. Ignition coils replaced, but did not solve the problem. Subsequent analysis indicated coolant in the combustion chamber due to a failed head gasket.
2012 Toyota Prius engine problems
moderate 44 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Failure mileage
Complaints
44
Recalls
0
Avg fix
$3,100
1crash
When does it fail?
Of the 44 engine complaints filed for the 2012 Toyota Prius, here's the actual mileage breakdown — failures cluster heaviest at 125,000-150,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Owners have filed 44 engine complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Among the 12 model years of Toyota Prius in our records for engine problems, this one ranks #3 by owner-complaint volume.
What owners are reporting 2 most recent
Tl* the contact owns a 2012 Toyota prius. While driving at an unknown speed, the check engine indicator illuminated and the vehicle vibrated. The vehicle was taken to Toyota vallejo (201 auto mall pkwy, vallejo, ca 94591, (707) 552-4545) where it was diagnosed that the head gasket was blown out and the engine needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware…
Had engine trouble with your 2012 Toyota Prius?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2012 Toyota Prius?
It's a documented issue but not catastrophic. 44 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Across the 33 complaints that reported odometer mileage, most engine failures cluster between 64,452 and 137,000 miles, with the median around 94,245. A quarter of owners report trouble before 64,452; a quarter make it past 137,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2012/Toyota/Prius.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.