2018 Toyota Prius Engine cooling Problems
- Complaints
- 3about this part
- Share
- 8%of 37 total for the year
- Median mileage
- 89,682miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 3 complaints about the engine cooling of the 2018 Toyota Prius, 8% of the 37 complaints for this model year. Where a mileage was given, the median is 89,682 miles.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“The contact owns a 2018 Toyota Prius. The contact stated that while driving at an undisclosed speed, the engine constantly overheated. An unidentified warning light was flashing on the instrument panel. An independent mechanic inspected the vehicle and became aware that the coolant reservoir was empty. One month later, the same failure reoccurred. A second independent mechanic inspected the vehicle, and the coolant reservoir was empty. The vehicle was taken to a dealer. The dealer diagnosed the vehicle with a coolant leak into the head gasket. …”
NHTSA complaint #11746813, filed 2026-06, 188,000 miles“The contact owns a 2018 Toyota Prius. The contact stated while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer where it was diagnosed with a failed heat exchanger, catalytic converter, and exhaust system. The contact was informed that the heat exchanger, the catalytic converter, and the exhaust system needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 89,682.”
NHTSA complaint #11650717, filed 2025-03, 89,682 miles“The contact owns a 2018 Toyota Prius. The contact stated that while having a routine oil change, the contact was made aware that there was no coolant in the coolant reservoir. No warning lights were illuminated. The contact was constantly adding coolant to the coolant reservoir; however, the following day the coolant reservoir was empty. The failure had occurred on several different occasions. The vehicle was taken back to the residence. The vehicle was not diagnosed or repaired. The contact researched and was made aware of TSB Number: 013519; however, the VIN was not included. …”
NHTSA complaint #11757394, filed 2026-08, 89,100 milesRelated service bulletins
- 10253223Mar 4, 2024This is to advise of various price adjustments that will affect Toyota Genuine Motor Oil and Long Life Coolant, effective March 1, 2024. These products are ordered through the…
- 10183281Oct 21, 2020TT: HVAC drain tube is found to be blocked/clogged.
- 10179791Aug 31, 2020TT: Any HVAC repair requiring reassembly of the quick connect fitting between the suction hose sub-assembly and the suction pipe sub-assembly located at the top right of the…
- 10179698Aug 5, 2020TSB: Some 2003 ? 2020 model year Prius, Prius C, Prius V; 2006 ? 2019 model year Highlander Hybrid Vehicle; 2007 ? 2020 Camry Hybrid Vehicle; 2013 ? 2020 model year Avalon Hybrid…
- 10179602Aug 5, 2020TSB: Some 2003 ? 2020 model year Prius, Prius C, Prius V; 2006 ? 2019 model year Highlander Hybrid Vehicle; 2007 ? 2020 Camry Hybrid Vehicle; 2013 ? 2020 model year Avalon Hybrid…
- 10178524Jul 30, 2020TT: HVAC drain tube is found to be blocked/clogged.
- 10166037Sep 26, 2019TSB: Some 2016 ? 2019 model year Prius and 2017 ? 2019 model year Prius Prime vehicles may exhibit one or more of the following conditions due to a coolant leakage at the front…
- 10131893Mar 27, 2017TT: Rev2 Some Customers may complain about a Hybrid Vehicle Battery cooling system warning message. This warning message may appear when the HV Battery cooling system loses…
Engine cooling: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2022 | 1 | 4% |
| 2019 | 1 | 3% |
| 2018 | 3 | 8% |
| 2017 | 1 | 1% |
| 2016 | 1 | 1% |
| 2012 | 1 | 0% |
| 2011 | 5 | 1% |
| 2010 | 33 | 1% |
| 2009 | 7 | 1% |
| 2008 | 16 | 1% |
| 2007 | 17 | 1% |
| 2006 | 20 | 1% |
| 2005 | 64 | 6% |
| 2004 | 89 | 15% |
| 2003 | 11 | 11% |
| 2002 | 11 | 7% |
| 2001 | 18 | 11% |
Other parts of the 2018 Toyota Prius
6 complaintsVisibility (wipers, defrost, mirrors)
6 complaintsExterior lighting
5 complaintsBrakes
4 complaintsVehicle speed control
4 complaintsAir bags
3 complaintsEngine
3 complaintsBody and structure
3 complaintsElectrical system
2 complaintsFuel system
2 complaintsSeats
2 complaintsTransmission and drivetrain
2 complaints
← All problems reported for the 2018 Toyota Prius
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 27, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology