Rough Idle and Flashing Check Engine Light?

Discussion in 'Technical Discussions' started by LC2183, Jul 14, 2020.

  1. LC2183

    LC2183 New Member

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    I don't know what this means. I hope its not serious, but does anyone know why my 06 Tahoe would be idling rough and having a flashing check engine light? The light flashed for a couple of minutes while I was driving and the car rough idles when I first start it up then quits after a while. Any help is greatly appreciated. Thanks!
     
  2. Goodoldchevy

    Goodoldchevy New Member

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    Hopefully, I can save you some time I had the same thing and after throwing a bunch of money at it, it turned out to be low compression. Do yourself a favor and start with a compression check, before anything. My mileage was at 208K which I considered low for a LS...
     
  3. LC2183

    LC2183 New Member

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    I will check that, thank you!!!! Really, that's considered low mileage?! Well then I'm really glad I bought this model!
     
  4. Goodoldchevy

    Goodoldchevy New Member

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    Yes, I have a 2000 Silverado with over 400k as well and it will still boil the tires off, just a little rear main leak, only changed the thermostat on that one, oh and a axle seal. Just keep a eye on the oil pressure and if it gets low change the o-ring on the oil pickup, they crack and act like a broken straw and it will serve you basically until you get tired of it.
     
  5. LC2183

    LC2183 New Member

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    So, could the o-ring maybe be the cause of an oil leak too? We're trying to get that figured out too. Other than that, this Tahoe is in great shape lol
     
  6. Goodoldchevy

    Goodoldchevy New Member

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    No, that one is internal under the oil pan and causes lifter ticking and oil starvation to vital parts of the engine. You take the oil pan off and it seals the oil pickup tube to the oil pump. It looks difficult, but really is not if you take your time, most of the Tahoe is really well engineered, so tuff but not impossible. Think of a cracked straw in your drink...same concept, they just get old and brittle.

    There are a couple common leak spots...rear main(check by taking off little round plug on bell housing and seeing if oil is all over in there. Up high behind the intake manifold is the cam sensor and oil pressure sender (leaks through the plug itself or the threads) it can leak quite a bit(only buy GM sensors I have seen new other ones leak brand new) and of course valve cover gaskets. There are a few others, but those I seen the most.
     
  7. LC2183

    LC2183 New Member

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    I've heard sensors is pretty common and my husband is skeptical about that being the cause lol. We will have to check that definitely. And we'll check the rear too just in case. Thank goodness you know your stuff! We've been relying on YouTube for advice lol
     
  8. Goodoldchevy

    Goodoldchevy New Member

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    Harbor freight has a good cheap inspection camera that is invaluable for checking bad places, pick you up one and clean the engine real good with some gunk and then check it with the camera, they are pretty nice you can even get into the cylinders via the spark plug holes. A lot of the Youtube videos are real good to learn stuff, I have been taught quite a bit through them over the years.
     
  9. LC2183

    LC2183 New Member

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    I will definitely let my husband know, thank you!!!