1. Attachments are working again! Check out this thread for more details and to report any other bugs.

2011 Prius Overheating

Discussion in 'Gen 3 Prius Main Forum' started by Mochosla, Apr 4, 2022.

  1. Mochosla

    Mochosla Junior Member

    Joined:
    Mar 22, 2021
    10
    2
    0
    Location:
    Southern California
    Vehicle:
    2011 Prius
    Model:
    XLE
    Hello everyone. I did some searches but wasn't able to find an answer to my question. I have an issue with my 2011 Prius where it overheats on the freeway during the first 2 miles. The high temp light goes on, stays on for a minute, and then turns off. I know it is overheating because the car is pushing hot coolant through the reservoir cap. I have replaced the thermostat, serviced the EGR valve (it was nasty but now is nice and clean), verified the valve in the catalytic works, replaced the coolant temp sensor, etc. and the problem persists. The pump makes what I believe is normal noise but I know it is working as I can see the coolant circulating in the reservoir. I just ordered a new pump and will replace it even though I have my doubts but the car has 150K miles so why not. Now, I see the fans turn on when I first turn on the car. However, I do not see them working when the car is hot. I pulled over yesterday right after I got the temp light and the fans were off. Can someone tell me where the fan switch is located and how to test it? I don't have an ODB computer so I can't really look at the coolant temp.

    As side information, I took the car to the dealer and the guy tells me that the issue is most likely a blown head gasket and wanted $570 just to diagnose it!!! I was like, the engine runs smooth and has no other issues. From what I've heard, blown gaskets are followed by misfiring of the engine and other symptoms. Correct? I did not leave the car with the dealer.

    Any help will be greatly appreciated.

    Thank you!
     
    #1 Mochosla, Apr 4, 2022
  2. michaud85

    michaud85 Member

    Joined:
    Jan 19, 2020
    55
    41
    0
    Location:
    Salem
    Vehicle:
    2010 Prius
    Model:
    V
    I bought a Chinese cable and it came with techstream worked great for my Prius. For coolant system testing. Check ebay

    you should try bleeding the system. Maybe do a full coolant flush.

    I recently made a post diagnosing similar problems.

    Brand new coolant pump died | PriusChat
     
    #2 michaud85, Apr 10, 2022
  3. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,675
    39,222
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Might be the fans not operating correctly (as you're suspecting): higher rpm freeway driving raises the coolant temp, trips the warning light, then the higher windspeed coming through the front grill cools it down.

    Good idea: the water pumps have a plastic impeller which can fail, and a few members here have recommended 150K as a limit for replacement.

    Maybe try another dealership? Did they share their reasoning for suspecting head gasket failure? A boroscope inspection and/or a leak-down test are good for checking head gasket integrity. Boroscope you can DIY relatively easily. For leak-down you're pressurizing a cylinder when it's at TDC of the compression stroke. There is a special valve set, and you need compressed air, but maybe you can do a poor mans version with the a compressor tester hose with the schrader valve taken out.

    How long have you had the car, since new? Any chance there's a stop-leak product (typically used to seal leaking head gaskets) in there?

    You cleaned the cooler as well, the component beyond the valve? Also, have you cleaned the intake manifold? It has EGR passageways that clog too. More info in my signature.
     
    #3 Mendel Leisk, Apr 10, 2022
  4. Mochosla

    Mochosla Junior Member

    Joined:
    Mar 22, 2021
    10
    2
    0
    Location:
    Southern California
    Vehicle:
    2011 Prius
    Model:
    XLE
     
    #4 Mochosla, Apr 10, 2022
  5. Mochosla

    Mochosla Junior Member

    Joined:
    Mar 22, 2021
    10
    2
    0
    Location:
    Southern California
    Vehicle:
    2011 Prius
    Model:
    XLE
    I don’t know what I did with my previous response but it failed. So, I received the new water pump and took the old one out. After I took it out, I plugged it in and turned on the AC on the car and was able to tell the pump wasn’t running normally. It would run and stop, run and stop. Also, when it run, it wasn’t very fast. I turned it by and and was able to tell it wasn’t running freely. At least nowhere near as free as the new one. I plugged the new one in and saw how fast it runs so I knew I had a bad pump. I replaced, tested the car and it the temp light did not turn on anymore. Also, I saw the fans running just fine. I was only able to test the car once as we left on vacation but as soon as im back, I will drive it every day and hope the issue will be resolved.

    I am a bit confused as to why the pump was getting stuck as it really doesn’t have many moving parts. It is like a sealed electric motor but oh well, if that was the issue, im happy it is solved now.

    Thank you for your replies.
     
    #5 Mochosla, Apr 10, 2022
    Mendel Leisk likes this.
  6. 2010moneypit?

    2010moneypit? Active Member

    Joined:
    Oct 26, 2021
    314
    122
    0
    Location:
    Beaumont ca
    Vehicle:
    2010 Prius
    Model:
    V
    Was your pump Aftermarket? Be careful if it was aftermarket pumps have a lot of problems.
     
    #6 2010moneypit?, Apr 11, 2022
  7. Mochosla

    Mochosla Junior Member

    Joined:
    Mar 22, 2021
    10
    2
    0
    Location:
    Southern California
    Vehicle:
    2011 Prius
    Model:
    XLE
    it was. Honestly, if it gives me 6 months, I will be fine and replace it with an original one. I just wanted to figure out what the issue was.
    Thank you.
     
    #7 Mochosla, Apr 11, 2022
    2010moneypit? likes this.
  8. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,421
    3,410
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    The impeller will swell and rub on the sides.
    There is a very small rubber "o" ring and a washer that hold it in place.
    2 weeks ago I replaced mine when I cleaned the egr circuit.

    Mine was original with 267,000 miles on it. It spun easily, and still looked new.
    I left it in, but when I was easing the pump into place, I dropped it, which broke off
    the circular part from the fins. :( So I put the new one in. I had no problems.
    $40 for the impeller, and $10 for the pump seal. A lot less than $250 for a new pump!

     
    #8 ASRDogman, Apr 11, 2022
  9. 2010moneypit?

    2010moneypit? Active Member

    Joined:
    Oct 26, 2021
    314
    122
    0
    Location:
    Beaumont ca
    Vehicle:
    2010 Prius
    Model:
    V
    Where did you buy the impeller at? Is it OEM?
     
    #9 2010moneypit?, Apr 11, 2022
    Mendel Leisk likes this.
  10. Minh

    Minh Junior Member

    Joined:
    Aug 22, 2018
    22
    4
    0
    Location:
    Sacramento
    Vehicle:
    2005 Prius
    Model:
    N/A
    I have similar issues with my Prius. I have a 2011. Changed out engine, water pump, sensor and thermostat. I have issue when I drive high speeds 70-80 mph up hill. Reservoir very hot almost to boiling temperature. Temp red light would turn on or flash and then when I slow down it will eventually turn off. My mechanic replaced literally everything minus the radiator and the inverter coolant pump. Can anyone please help????

    No codes or no check engine lights just the red light engine temperature turns on when driving high speeds up hill for long periods of time.

    Is the issue temp sensor on EGR pipes?

    My mechanic has replaced with all OEM parts. Any advice?

    Toyota service rep says might be inverter water pump, radiator clogged up, or water pump.
    Just had Toyota dealership diagnosed and they check for any leaks so it’s not the engine. They said water pump and thermostat. My mechanic replaced those 2 parts. I thought I was in the clear but I wasn’t. The car still overheats when driving high speeds 75-80 mph for long periods of time and red temperature light turns on again uphill at high speeds. Anyone please help and TIA

    just replaced thermostat and water pump with OEM parts for the 2nd time. Please help
     
    #10 Minh, Mar 12, 2023
  11. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    6,421
    3,410
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    Are you 100% certain you are getting ALL the air out of the system?
    Are you using Toyota coolant?
    Has the radiator been checked to make sure it's NOT clogged?
    Is the radiator and condensor clear of any obstruction?
    Has the heater core been check to make sure it's not clogged?

    Do you put and of the stop leak in the cooling system?
    If so, you need a new radiator and heater core and need to clean all the small
    passages that are blocked.

    Some say white vinegar will dissolve it, though I have not tried it.

     
    #11 ASRDogman, Mar 13, 2023
  12. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,675
    39,222
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    @Minh:

    1. Have you had the car since new, and if not: at what miles did you buy it?
    2. What's the miles now?
    3. Has the EGR system and intake manifold ever been cleaned?
     
    #12 Mendel Leisk, Mar 13, 2023
  13. Minh

    Minh Junior Member

    Joined:
    Aug 22, 2018
    22
    4
    0
    Location:
    Sacramento
    Vehicle:
    2005 Prius
    Model:
    N/A
    @Mendel Leisk thank you for responding.
    No I bought it used. 345k
    Now at 347k miles
    Need to check with mechanic on that EGR system and intake manifold. Will find out and post
     
    #13 Minh, Mar 14, 2023
    Mendel Leisk likes this.
(You must log in or sign up to post here.)