Aluminum head spark plug thread repair.

Discussion in 'The Okie Corral' started by Adjuster, Jan 31, 2013.

  1. Adjuster

    Adjuster

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    My neighbor was replacing his spark plugs and boogered up the first few threads in one of the holes. Now the new spark plug won't catch the threads and screw in. Any tips and/or tricks?



    /
     
  2. dizmodeus

    dizmodeus

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    Buy a tap coat it in grease and recut the threads then start the engine without a plug in that hole to blow out any crap that didn't stick to the grease in the tap
     

  3. janice6

    janice6

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    Try running a tap through it to just "clean up" the existing threads and see if it works. Otherwise there is a Helicoil drill/tap/handle set to do this and it isn't trivial or cheap. Gotta keep particles from falling into the cylinder head.
     
  4. aircarver

    aircarver Descent Terminated Silver Member

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    Keep bumping the thread until NEOH212 sees it .... :supergrin:

    She has written fairly extensively on repairing this without removing the head.

    :bump:

    .
     
  5. SPIN2010

    SPIN2010 Searching ...

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    Taps with grease, Heli-coil, and even one of the old plugs gone over with sandpaper (800 -1000), then hand fed down slowly until it grabs a thread.

    Now if it is your one of your less liked family members (i.e. MIL, SIL etc.) you can use high temp epoxy once only. :supergrin:
     
    Last edited: Jan 31, 2013
  6. HollowHead

    HollowHead Firm member

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    This. Anal retentives like me can also degree the cylinder so the only the exhaust valve is open and run a leaf-blower up the tailpipe. Air howls out the spark plug hole while you tap it. HH
     
  7. PEC-Memphis

    PEC-Memphis Scottish Member

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    If it actually needs an insert, (rather than just chasing the threads)You might check-out the time-sert. It is better than heli-coil.

    That's all we've used on older Porsche cases where the studs pulled out of the case - actually better than new. We've actually used time-serts on rebuilds where the studs didn't pull out just because they are better than the original design.
     
  8. aircarver

    aircarver Descent Terminated Silver Member

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    So nobody is taking the cylinder head off to do this ... :outtahere::supergrin:

    .
     
  9. Clem Eastwood

    Clem Eastwood

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    exactly. however, im guilty of fixing some spark plug threads on a couple of ford 4.6s without dissassembly. afterwards you go after the metal in the cylinder using a homemade adapter and the shop vac. :supergrin:
     
    Last edited: Feb 1, 2013
  10. knightkrawler00

    knightkrawler00

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    I've never pulled a head to fix one. Done plenty if the Ford modular engines. There is a nice kit available to install a time-sert that you may be able to rent or borrow.
     
  11. LEO/Dad

    LEO/Dad Navy Veteran

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    I don't get in any hurry when removing plugs, particularly in an engine for the first time. When I break one free, I will run it back in. I will repeat this process until the plug is out. Half round out/half round back in. Or something like that. You get the point. I have never had a problem. Aluminium heads are tricky. I have outboards and mowers to deal with also.. Oh yes, I use anti-freeze compound (Loctite) on the new plugs threads. I think using a regular plug socket with the rubber insert certainly helps for a straight alignment when installing to get the threads started. Good luck.
     
    Last edited: Feb 1, 2013
  12. aircarver

    aircarver Descent Terminated Silver Member

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    How 'bout soaking them in (Kano) Kroil 24 hours before applying torque to them ?

    .
     
  13. Ruble Noon

    Ruble Noon "Cracker"

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    I recommend using this on anything screwing into aluminum, including spark plugs.

    [​IMG]
     
  14. byf43

    byf43 NRA Patron Life Member

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    Tell your neighbor to just put some JB Weld on the sparkplug and with a little downward pressure, start the threads.

    Do NOT stop installing the sparkplug, until the sparkplug is fully seated and torqued.

    Let the engine 'sit' for 24 hours.

    Start it up, take it to the nearest dealer and TRADE that truck for a new one!!!!!!!!!



































    j/k. . . . or was I?????
     
    Last edited: Feb 1, 2013
  15. onearmsteve

    onearmsteve

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    they sell spark plug thread chasers i would use one of them than using a tap. dont want to recut the threads just fix em
     
  16. BigDeeeeeeee

    BigDeeeeeeee Reluctantly Deplorable!

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    [ame="http://www.amazon.com/Powerbuilt-640811-Back-Tap-Thread-Repair/dp/B0014FGVVW/ref=pd_sim_sbs_hi_1"]Powerbuilt 640811 14mm Back-Tap Thread Repair Tool : Amazon.com : [email protected]@[email protected]@http://ecx.images-amazon.com/images/I/[email protected]@[email protected]@313CcLsXE8L[/ame]
    [ame="http://www.amazon.com/KD-Tools-Internal-Thread-Rethread/dp/B000J4K01G"]KD Tools (KD 3545) 14mm Internal (Thread Chaser) Spark Plug Rethread Tool - [email protected]@[email protected]@http://ecx.images-amazon.com/images/I/[email protected]@[email protected]@21ctc8rC-7L[/ame]

    I like the leafblower idea, beats the hell out of shop vac.
     
    Last edited: Feb 1, 2013
  17. aircarver

    aircarver Descent Terminated Silver Member

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    Ah Yes !

    ... but did the factory do that in the first place ? ... :whistling:

    .
     
  18. Bill Powell

    Bill Powell Cross Member CLM

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    I've done several Mercedes 450 heads, and one 280, and had no problem. I used gobs of grease on the tap drill and the heli-coil tap.
     
  19. Unlocked

    Unlocked 4 8 15 16 23 42 CLM

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    Time-sert (spelled something like that i think) or helicoil. There are some good videos on youtube (or at least used to be) showing methods of doing this.
     
  20. onearmsteve

    onearmsteve

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    anti seize is a common practice at the dealership when changing spark plugs and is recommended in the Manuel