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Check Engine Light On with rattling sound

Discussion in 'Gen 3 Prius Technical Discussion' started by Zakir, Jul 1, 2024 at 4:54 PM.

  1. Zakir

    Zakir New Member

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    HI
    I have been driving my 2011 Prius for the past six years. When I purchased it in 2018, the mileage was 85,000. Currently, it has 250,000 miles. Recently, I've noticed a rattling noise when starting the car in the morning or intermittently while driving, accompanied by the check engine light coming on.

    I took the car to Midas, where they replaced the ignition coils for the first and second spark plugs. However, the check engine light still turns on and off, and the rattling or shaking persists. The technician recommended an EGR cleaning, which would cost an additional $800.

    Given this situation and my lack of alternative transportation, what would you advise?
     
    #1 Zakir, Jul 1, 2024 at 4:54 PM
  2. ASRDogman

    ASRDogman Senior Member

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    It's likely your head gasket. Have you noticed your coolant level going down?
    Don't waste your time with the spark plugs or coils.

     
    #2 ASRDogman, Jul 1, 2024 at 7:23 PM
    Brian1954 likes this.
  3. bisco

    bisco cookie crumbler

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    I have to give Midas credit for understanding the egr problem, that’s more than most Toyota dealers do
     
    #3 bisco, Jul 2, 2024 at 4:23 PM
  4. Dduelin2

    Dduelin2 New Member

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    It's easy to block off the EGR valve to check if it's sticking and causing the intermittent rough running condition reported. If you have a lead on a trusted mechanic ask him for check the trouble code(s) behind the check engine light and perform a compression leak down test to check integrity of the head gasket.
     
    #4 Dduelin2, Jul 2, 2024 at 6:05 PM
  5. Eddie25

    Eddie25 Active Member

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    Don't do the EGR cleaning.

    The codes were obviously cylinder 1 and 2 misfires, so they went with the simplest option of replacing the coils and plugs on those two cylinders, but the most likely issue is a blown head gasket which leaks coolant into those cylinders and causes the misfires.

    At the very least ask the shop to focus on diagnosing a head gasket, but you should be figuring out the best option for getting the head gasket replaced, or moving on from the car. Dealers are definitely not it, I'd find either a trusted shop or look around for hybrid specialists and ask them specifically if they do 3rd gen prius head gaskets. If you get a head gasket done, ask specifically if EGR cleaning is part of the job, it should be.
     
    #5 Eddie25, Jul 2, 2024 at 9:13 PM
  6. AzusaPrius

    AzusaPrius Senior Member

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    EGR cleaning is its own service and never included with a HG repair.
     
    #6 AzusaPrius, Jul 2, 2024 at 9:24 PM
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