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MAP sensor fell into manifold

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by FergusonT, Jan 29, 2013.

  1. FergusonT

    FergusonT New Member

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    Long story short, the MAP sensor broke and the piece that goes into the manifold fell into the manifold. I would assume this is just - Take manifold off, find the piece, reinstall manifold -. Anything I should know? I have never removed an intake manifold, plan on going by the Haynes manual on this one.

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    BTW, the engine was off and has not been turned over since.
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  2. Pikey

    Pikey Moderator

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    is the part that fell in metal? maybe you can fish it out with a magnet.
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  3. FergusonT

    FergusonT New Member

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    I am not sure actually...but I guess its worth it to try. Its the end of the sensor that sticks down into the intake manifold, from what I remember it is all rubber seal on the outside. The way it broke off I am assuming its all plastic.

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    I guess what I need to know is the best way to do the gasket. Where to use RTV.
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  4. TimTom64b

    TimTom64b New Member

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    Buy quality gaskets... And RTV at each end of the intake gasket meets the little gaskets on each end of the intake. Be sure you get yourself a gasket scraper... And plug all the intake ports and lay an old hand towel in the block to catch all the chunks before you start scraping. Another tip... Be sure you mark the distributor position on the intake and rotor position under the cap. This way when you re-install the timing will be close.
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  5. FergusonT

    FergusonT New Member

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    No distributor on this truck thank god.

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    Im an idiot, I never said what truck...its a 1999 Silverado 5.3.
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  6. a.graham52

    a.graham52 New Member

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    take the intake tube off and open the throttle and make sure you cant see it first. if you can get a pick or put a small loop in a coat hanger and use a bunch of grease a tthe end to grab the piece. also you truck has an upper and lower intake. i dont think you will need rtv for seperating the lower and upper intake. i know the some of them use an oring that you can reuse if you choose.
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  7. TRPLXL2

    TRPLXL2 New Member

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    Well I thought I had a picture of my truck intake, but I can't find it. 99 was the first year for "DRY" intake manifolds. There are 2 gaskets, each one is made of plastic and each intake port has a rubber o-ring. These are reusable gaskets, BUT you might have an o-ring that gets mangled when you remove the intake so be prepared to have to go and get new gaskets. ($14.99) Felpro from autozone or wherever.

    The MAP sensor is also plastic, there is no metal to it at all.
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  8. FergusonT

    FergusonT New Member

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    I got the throttle body off and looked into the manifold. Cant see back far enough to where the MAP sensor was sitting. Looks like the manifold has 2 chambers, all I could see at the back of the first chamber was a small hole that led back further to where the map sensor sits.
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  9. shibby2oo8

    shibby2oo8 New Member

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    dry manifold like I said in the other post, you will need to replace the intake o-rings. No point will need rtv or even coolant if you unbolt the throttle body and leave it on the engine. Its a really easy job, just make sure to put balled up sheets of heavy papertowel into the intake ports on the head and remember to take them out too. No big
    #9
  10. FergusonT

    FergusonT New Member

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    #10
  11. shibby2oo8

    shibby2oo8 New Member

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    Also, I did spill coolant, I removed the hose from the drivers side of the throttle body.[/QUOTE]

    You could have left it on but like i said but no matter. If you have a 3/8 or 1/4 torque wrench use it because if you dont tighten the intake right it will warp.
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  12. FergusonT

    FergusonT New Member

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    Alright got the manifold off, peaked into the port for cylinder 8....and there sits the little rubber piece from my MAP sensor, sitting on top of the closed valve.
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  13. j cat

    j cat Active Member

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    so maybe now with a good MAP the engine will run good. I suspected that your MAF was messed up.
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  14. FergusonT

    FergusonT New Member

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    You could have left it on but like i said but no matter. If you have a 3/8 or 1/4 torque wrench use it because if you dont tighten the intake right it will warp.[/QUOTE]


    Yeah I saw your post after I had already done it...oh well

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    With the codes I was getting, I am wondering if maybe it needed new intake gaskets anyways. Maybe I should replace the MAF as well.
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  15. FergusonT

    FergusonT New Member

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    Well well....Last night....snapped a manifold bolt..........
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  16. a.graham52

    a.graham52 New Member

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    removing or installign the bolt? time to invest in some broken bolt removal tools.
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  17. FergusonT

    FergusonT New Member

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    re installing, I got it out though. It snapped up high thank god. Just spent all day running around and calling places, can't find anywhere. Wandered around a junk yard for about 45 minutes, no gm 5.3 motors. Guess I gotta go through the stealership on this one.
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  18. j cat

    j cat Active Member

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    you better get a torque wrench and the torque specs. no reason to break these bolts easy on this hardware. also you must follow the proper torque proceedure . this is why bolts break and components get distorted. all these parts are soft ALUM>>>>.
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  19. TRPLXL2

    TRPLXL2 New Member

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    The dealership charges $1.35 for the bolt, and have them print off your torque specs. Take your vin # with you, so they give you the correct one's for your vehicle. The only thing I will say about it is the torque sequence is done in 3 passes on each bolt, staggered in a pattern like a star. Make sure you read it real close, because they go from inches-lbs, to ft-lbs. and it's easy to screw up!
    #19
  20. FergusonT

    FergusonT New Member

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    I've got the specs and the sequence from a haynes manual, the problem was I was using a bad torque wrench. I was using my dads old wrench, he goes "oooh yeah, I used that on my '67 Camaro back in the '70s." It had to have been off, it was saying 40lbs and it snapped a bolt.
    #20

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