GO FISHING, use SLABSAUCE Fishing Attractant
Results 1 to 9 of 9

Thread: removing a rounded off oxygen sensor

  1. #1
    Join Date
    Jan 2004
    Location
    Benneton (United Colors of)
    Posts
    3,067

    Default removing a rounded off oxygen sensor

    hi all. i tried to remove the oxygen sensor on my 92 m50 equipped vehicle with an oxygen sensor wrench/crowfoot, and found that i rounded it down significantly. after hitting it for about five cycles with a blow torch followed up with a soaking of pb blaster, i tried to remove it with a 22mm deep socket and breaker bar, and found that it only made the rounding worse. i also tried turning the body of the sensor with vice grips and a breaker bar, marking the position of the sensor relative to the manifold with a stripe of paint, and found that i only manage to twist the sensor body, and not budge the sensor nut any. is there anything else I can do, or do i have to put in a new hole? I was thinking about using a pipe wrench, but i don't want to screw up the nut anymore if there is another measure i can take. thanks.
    "..Torchinski v. Peterson that it is legal to carry a concealed weapon, so long the weapon is totally slick like a huge ass machine gun that you carry under a trench coat, like in the Matrix."


  2. #2
    Join Date
    Oct 2004
    Location
    Honolulu
    Posts
    3,105

    Default

    Try heating just the bung on the manifold and use a chisel and hammer to knock the sensor counter clock wise.

    You could cut the sensor down to the nut to get ready to weld on a bolt and try to go from there.


    Vee ave vays of dealing vid your kind...........

  3. #3
    Join Date
    Mar 2009
    Location
    Sydney
    Posts
    196

    Default

    Quote Originally Posted by ryan roopnarine View Post
    hi all. i tried to remove the oxygen sensor on my 92 m50 equipped vehicle with an oxygen sensor wrench/crowfoot, and found that i rounded it down significantly. after hitting it for about five cycles with a blow torch followed up with a soaking of pb blaster, i tried to remove it with a 22mm deep socket and breaker bar, and found that it only made the rounding worse. i also tried turning the body of the sensor with vice grips and a breaker bar, marking the position of the sensor relative to the manifold with a stripe of paint, and found that i only manage to twist the sensor body, and not budge the sensor nut any. is there anything else I can do, or do i have to put in a new hole? I was thinking about using a pipe wrench, but i don't want to screw up the nut anymore if there is another measure i can take. thanks.
    LOCKTITE have a new freezer spray that you spray the same way as you do WD40.
    As it minutely shrinks the bolt (your sensor) the lubricants are supposed to wick into the threads and provide lubrication.

    Its new and I haven't tried it. But its in the trade magazines as better than WD40 type sprays that rely on soaking penetration.

    Good luck.
    ss2115.

    BMW 525i Touring - 1993 (current drive car).
    DS23 Citroen Safari - 1974 (restoration and modifications).
    Golf MkIII - 1997 (fun car and daughters learn-to-drive car)

  4. #4
    Join Date
    Jan 2004
    Location
    Benneton (United Colors of)
    Posts
    3,067

    Default

    Quote Originally Posted by ss2115 View Post
    LOCKTITE have a new freezer spray that you spray the same way as you do WD40.
    As it minutely shrinks the bolt (your sensor) the lubricants are supposed to wick into the threads and provide lubrication.

    Its new and I haven't tried it. But its in the trade magazines as better than WD40 type sprays that rely on soaking penetration.

    Good luck.

    i used up a whole can of CRC's freezing penetrant on the fitting with no effect, so I doubt that locktite's offering will do much better.

    thanks though.
    "..Torchinski v. Peterson that it is legal to carry a concealed weapon, so long the weapon is totally slick like a huge ass machine gun that you carry under a trench coat, like in the Matrix."


  5. #5
    Join Date
    Mar 2006
    Location
    East Brunswick, New Jersey
    Posts
    879

    Default

    Remove the cat to do it on the bench. I am a pessimist.
    '01 540it, 6/01
    '03 325i 5 speed, 9/02
    '10 535ix. 9/09
    '10 mini 6 speed
    '15 mini countryman 6 speed

  6. #6
    Join Date
    Sep 2007
    Location
    Seattle, WA
    Posts
    1,036

    Default

    Quote Originally Posted by yaofeng View Post
    Remove the cat to do it on the bench. I am a pessimist.
    +1

    I tried pull the O2 on a '95 M50B25TU (should have the same exhaust pipes as yours) with the exhaust in and I couldn't get it out. Dropped the very, very f'in heavy exhaust and was able to get it out once the exhaust was out from under the car.

    I'd drop the exhaust, grab a pipe wrench, and go to it after heating that thing up cherry red with a torch. But trust me, you can get much better angles and much better leverage with the exhaust off the car.
    Cosmos Black/Black 1995 540iA M-Sport
    BMW Individual Exclusive Edition, 1 of 65 total, 9/25/95 Build

  7. #7
    Join Date
    Apr 2006
    Location
    Chicago, Il. U.S.A.
    Posts
    4,243

    Default

    Add my vote to the pipe wrench idea. Brute force and fire are your friends now.
    "The gas pedal wouldn't go to the floor if it weren't meant to be there"

  8. #8
    Join Date
    Jan 2007
    Location
    Dayton Ohio
    Posts
    1,483

    Default

    I second that. Drop the exhaust and fire it up. If you don't have acetylene I would use mapp gas and pb blaster. If the sensor breaks then drill it and use an ez out.

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

    Default

    Big fat Vise grip (not needle nose vise grip) on the the O2 bolt... First, make sure you can grab it easily enough so you don't fumble when trying to grab it while it is hot. Then remove that vise grip.


    Torch that O2 sensor until you see the change of color in the flame... WIth propane, it might take about a minute... MAPP is faster... but whichever you have is fine. The longer you heat it up, the better chance of getting it out.

    Once the O2 sensor is hot, put the visegrip on it and bang it loose.

    If you put the visegrip on the O2 sensor, you are dissipating that heat so you can't get it hot enough regardless how long you heat it.

Similar Threads

  1. $775 Oxygen sensor in NC
    By Jon K in forum 5 Series BMW
    Replies: 42
    Last Post: 11-01-2007, 07:04 AM
  2. Need help removing an oxygen sensor.
    By nmwaldron in forum 5 Series BMW
    Replies: 20
    Last Post: 10-04-2006, 07:32 PM
  3. which Oxygen sensor is #2 ??
    By lvngdead in forum 5 Series BMW
    Replies: 4
    Last Post: 06-10-2006, 01:46 AM
  4. No oxygen sensor !!!
    By Ali in forum 5 Series BMW
    Replies: 11
    Last Post: 04-23-2005, 02:54 AM
  5. Oxygen Sensor
    By jbw535i in forum 5 Series BMW
    Replies: 10
    Last Post: 03-24-2004, 11:38 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
  •