really awful
Crashes / Fires:
1 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
67,952 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2009 Toyota Prius engine problems

engine problem

Find something helpful? Spread the word.
Get notified about new defects, investigations, recalls & lawsuits for the 2009 Toyota Prius:

Unsubscribe any time. We don't sell/share your email.

2009 Toyota Prius Owner Comments

problem #8

Dec 142015


  • 65,000 miles


The contact owns a 2009 Toyota Prius. The contact stated that while driving 50 mph, the engine started to rev and vehicle accelerated uncontrollably. The vehicle was restarted after waiting a movement but the failure recurred. The vehicle was towed to an independent mechanic where it was awaiting a diagnosis. The manufacturer was not made aware of the failure. The failure mileage was 65,000.

- Rehoboth Beach, DE, USA

problem #7

May 012015

Prius 4-cyl

  • 130,000 miles
The 2009 Prius engine has a defect in the seals allowing oil to seep into the engine and be burned. This causes the motor to use extensively more oil than needed. Causing possible near failure. It must be critically maintained or the engine will run dry and destroy itself.

- Johnston, IA, USA

problem #6

Jul 072014


  • 75,985 miles
Water pump failure. 76,000 miles is premature for a waterpump.

- Roseville, CA, USA

problem #5

Nov 012014

Prius 4-cyl

  • 50,000 miles


Service engine light, code P1121, coolant recovery tank flow control valve bad. There is a service campaign on this for 2007 Prius and the problem is supposed to be solve for 2009 Prius. Also this is part of the emission control system, as the purpose of coolant recovery tank is the warm up engine sooner to pass emission test. Called Toyota dealer, not covered by emission warranty. This is a known and very common problem and Toyota is dragging its leg on it.

- Beaverton, OR, USA

problem #4

Oct 012014

Prius 4-cyl

  • 41,632 miles
Toyota dealer receipt: Check engine light on - coolant control valve stuck... replaced coolant control valve cost/$589.97 including $450 labor + engine water pump leaking coolant replaced engine water pump/ engine drive belt cost/$557.98 including $430 labor mileage!!! 41, 632 miles 2009 Prius total cost $1173.41. Customer complained to Toyota motor Corp and response was...no financial assistance -36,000 mile warranty has passed.

- Santa Monica , CA, USA

problem #3

Nov 142013

Prius 4-cyl

  • 65,000 miles
When my 2009 Toyota Prius reached approximately 65,000 miles, the check engine light came on, and the error code was P1121, indicating a problem with the coolant control valve. I took the car to my local Toyota dealership, and their charge for replacing the part was $400. The mechanic who inspected the valve said it was not closing securely. He said making the repair would not improve the car's performance or affect its value, and therefore he did not recommend making the repair. Unfortunately, I have realized that opting out of this repair does affect the car's safety. The check engine light is constantly on. Even if I manually turn it off, it comes right back on, so it is unlikely that I will be aware if other mechanical issues ever arise. My mother drives a 2008 Toyota Prius which just hit 65,000 miles, and her car produced the exact same error code. It is statistically impossible that two cars of the same make and model, only a year apart in age, in the same household, would produce identical error codes after reaching roughly the same mileage for any reason other than defective manufacturing. I believe this error code is the result of a manufacturing error that Toyota should address through a safety recall. Toyota's own mechanic admitted that the repair is financially impractical for customers, yet if the repair is not made, drivers are left without a functional check engine light which is a safety hazard.

- Austin, TX, USA

problem #2

Mar 042013

Prius 4-cyl

  • 81,000 miles
In an attempt to avoid oncoming calves on a county dirt road driver inadvertantly pulled steering wheel to the right and hit a tree at road side. Tree is twelve inched from road surface. Before seat belt restrained driver, driver's forward momentum broke the steering wheel. Driver was not injured. Went to local hospital er. Sheriff investigated. With the extensive damage to the front end of the vehicle the air bag should have deployed. It did not. Photos taken. Your organization is being notified as we feel the air bag should have deployed. We will also contact Toyota. Thank you. [xxx] information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Clarksville, AR, USA

problem #1

Aug 312012

Prius 4-cyl

  • 35,000 miles
The vehicle stalled out while I was driving, four times in about a mile - including once on a very busy road with no shoulder. The electrical error board lit up, the transmission reverted to neutral or park and I could not put the car back into drive. After I turned the car off, and then turned it back on, it went into drive but only for a short while before lights started flashing and it stalled again.

- Austin, TX, USA

Not what you are looking for?