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HOWTO Compression Test?

Discussion in 'General Tech and Maintenance' started by ohmstable, May 21, 2004.

  1. ohmstable

    ohmstable Senior Member

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    I bought a compression tester which basicly looks like a hose which screws into the sparkplug hole and a gauge. Now my question is, how the hell can I screw this into the sparkplug hole when its so deep in the head? Is there an adapter or something that I need along with this tester? Is there a special tester for honda's?
    I've also got a leakdown tester which is basicly the same issue again.

    Any info would be great.

    Ohmstable
     
  2. BigJ

    BigJ I'm just about that action Boss. VIP

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    For a compression tester you first remove spark plug wires, and then remove spark plugs themselves.

    Then you remove the fuel pump fuse(not sure exactly which one on top of my head) from the underhoodfuse box.

    Then you put the hose with the attachment that looks like it screw in, into the #1 spark plug hole. You twist the whole mechanism, the gauge and all to make it screw into the spark plug hole, make sure there isn't resistance, otherwise you can crossthread, which would be very bad.

    Then you after have it screwed in tightly, have someone turn the ignition until you can tell what the needle is pointing on for a few seconds at least, and you can get an accurate reading. Then repeat this for the other 3 cylinders.

    The readings shouldn't be off more thne 5-10psi at most.
     
  3. ohmstable

    ohmstable Senior Member

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    So basicly I just shove the hose with threaded adapter down the spark plug hole and thread it on? I guess tightened down as much as possible by twisting the hose?
     
  4. WetWilly

    WetWilly Senior Member

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    it doesnt have to be extremely tight and when you crank the engine look at the guage if it goes more than half way then to full compression that means its okay. You only need to crank it 3-5 times each cylinder, and it doesnt have to be the fuel fuse any fuse that disables the car from starting will do like the coil.
     
  5. ohmstable

    ohmstable Senior Member

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    thanks for the info..
    Now here's the twist.. can I do a compression test on an engine that is on an engine stand? There's no tranny, so there's no starter. Can I just crank the engine over by the crank bolt?
     
  6. Arachnid

    Arachnid Senior Member

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    seems possible...just make sure the bolt from the crank pulley doesn't come out. but i can relate to the compression working by hand.
     
  7. pissedoffsol

    pissedoffsol RETIRED

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    read the articles section. theres a how to there.
     
  8. swappyturbo

    swappyturbo New Member

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    oh just read the engines out....
    as long as your able to crank over the engine by the starter, should be good...
    I got a remote switch with crocodile clips for the starter motor, with engine and wires connected to battery...crank it over and do the cold test...you wont have any fuel going in so no no worries there...
     
  9. FLounder

    FLounder power hungry VIP

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    yes you can test compression without having a starter, it just takes longer.

    you should disable the fuel pump and the coil, unless you like fire and explosions in your car. also open the throttle to get a true reading.

    actually, just dont listen to any of the stuff these guys are telling you in this thread and do like pissedoffsol said....
     
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