GO FISHING, use SLABSAUCE Fishing Attractant
Page 1 of 2 12 LastLast
Results 1 to 10 of 18

Thread: cross threaded spark plug

  1. #1
    Join Date
    Jun 2004
    Posts
    114

    Default cross threaded spark plug

    So installing the first new spark plug i made the mistake of doing it with the ratchet, and cross threaded it half a turn. Then i tried it again another half turn... now its cross threaded 3 turns and im scared shitless. I bought a kit that will ream out the hole and then i can press in a new sleave, but i think you need to take the cylinder head off to clean out the chips, and theres no way im doing that. Should i drive it to the shop on 5 cylinders, im thinking of putting the plug in finger tight and driving it gingerly to the shop with the plug wire disconnected, what do you guys think? All 5 other plugs went in very easily, just my luck...

    Black/Black '90 535IM..... '65 Cal look vw bug

  2. #2
    Join Date
    Dec 2003
    Posts
    835

    Default

    Get a spark plug thread chaser. It is a tool just for this purpose.
    erased due to slander

  3. #3
    Join Date
    Jan 2008
    Location
    Quebec, Canada
    Posts
    608

    Default

    Quote Originally Posted by casurfer911 View Post
    So installing the first new spark plug i made the mistake of doing it with the ratchet, and cross threaded it half a turn. Then i tried it again another half turn... now its cross threaded 3 turns and im scared shitless. I bought a kit that will ream out the hole and then i can press in a new sleave, but i think you need to take the cylinder head off to clean out the chips, and theres no way im doing that. Should i drive it to the shop on 5 cylinders, im thinking of putting the plug in finger tight and driving it gingerly to the shop with the plug wire disconnected, what do you guys think? All 5 other plugs went in very easily, just my luck...
    2 Choices: Take out the cross-threaded plug and leave it empty and insulate the un-used spark plug wire to not short anything. (I don't know if the cylinder is going to be full of fuel by the time you get to the shop).

    Or

    Get it towed to a competant garage. They have a mini vacuum that fits in the spark plug hole to suck up the shavings otherwise you risk bending a exhaust valve with those shavings in there.

    Happened to a friend of mine. He called me after the cross-threaded 3 of the 6 cylinders on a rb20det (Skyline gts). Tried to start it and it ran TERRIBLE....wouldn't even idle. Got it towed and they re-threaded the spark plugs holes.


    BMW E34 1992 525i Touring

    RIP Touring...probably never going to drive you again...

  4. #4
    Join Date
    Feb 2006
    Location
    Oldham, England
    Posts
    3,078

    Default

    Quote Originally Posted by Martin in Bellevue View Post
    Get a spark plug thread chaser. It is a tool just for this purpose.
    x1.
    If the plug hole threads are in reasonable shape you should get away with it.
    Drive it with a loose plug and you risk blowing the plug out and wrecking the threads completely; without a plug and you have fuel vapour on a nice hot engine

  5. #5
    Join Date
    Apr 2006
    Location
    Chicago, Il. U.S.A.
    Posts
    4,243

    Default

    X2, not a big deal.
    Think you're shitting bricks? I did this once to a Ferrari.
    "The gas pedal wouldn't go to the floor if it weren't meant to be there"

  6. #6
    Join Date
    Jun 2004
    Posts
    114

    Default

    Anywhere in particular i can pick up a thread chaser tool, i stopped at kragen and the guys were clueless. Do these tools start from the back where the threads are still good and work outward to keep chips out of the cylinder?

    Black/Black '90 535IM..... '65 Cal look vw bug

  7. #7
    Join Date
    Feb 2006
    Location
    Oldham, England
    Posts
    3,078

    Default

    Quote Originally Posted by casurfer911 View Post
    Anywhere in particular i can pick up a thread chaser tool, i stopped at kragen and the guys were clueless. Do these tools start from the back where the threads are still good and work outward to keep chips out of the cylinder?
    Not sure where you are but they are widely available. They go from the outside-in so no need to take the head off. Check this one out:
    http://www.machinemart.co.uk/shop/pr...ive-hand-tools
    The groove is to collect the crap - you might smear a tiny bit of grease in there to collect any swarf.

  8. #8
    Join Date
    Jan 2004
    Posts
    4,150

    Default KD tools makes this one that threads from the inside out

    so you don't have chips falling into the cylinder. If you hunt around you should be able to find it locally

    http://www.restockit.com/14-mm-Internal-Thread-Chaser-Spark-Plug-Rethread-Tool-(KDT3545).html


  9. #9
    Join Date
    Feb 2004
    Posts
    4,894

    Default

    Any auto parts store has them... called Spark plug threader. Put grease on the threader to catch all the aluminum shavings.

    The key is to be absolutely sure you are threading it the way the spark plug goes in... It is easy to rethread them in different angle.

    Get the threader that is the same depth as the spark plug... there are other brand where it only goes in 1/2".

  10. #10
    Join Date
    Feb 2006
    Location
    Oldham, England
    Posts
    3,078

    Default

    Quote Originally Posted by Bill R. View Post
    so you don't have chips falling into the cylinder. If you hunt around you should be able to find it locally

    http://www.restockit.com/14-mm-Internal-Thread-Chaser-Spark-Plug-Rethread-Tool-(KDT3545).html
    Wow! Never seen one of those. Had to read it twice to make sure I understood it. Starts off with the 'good' threads at the bottom and works its way out?. Not cheap but a hell of a lot quicker and cheaper than taking the head off. I break NGK plugs for fun so will be making a mental note of this. Nice one! :-)

Page 1 of 2 12 LastLast

Similar Threads

  1. Spark plug
    By specialguess in forum 5 Series BMW
    Replies: 29
    Last Post: 04-14-2010, 10:00 AM
  2. spark plug application chart, plug gap, torque
    By shogun in forum 6 Series BMW
    Replies: 0
    Last Post: 10-15-2009, 12:33 AM
  3. complete spark plug cross reference
    By shogun in forum 5 Series BMW
    Replies: 3
    Last Post: 02-13-2009, 05:50 PM
  4. m20 spark plug gap
    By pong in forum 5 Series BMW
    Replies: 4
    Last Post: 04-05-2008, 02:11 PM
  5. Cross-threaded spark plug and coolant leak
    By Rus in forum 5 Series BMW
    Replies: 4
    Last Post: 11-10-2005, 07:00 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •