Results 1 to 15 of 15

Thread: P0174 Intermittent

  1. #1
    Join Date
    Nov 2017
    Location
    Morrisville, NC
    Posts
    6
    My Cars
    2001 330ci

    P0174 Intermittent

    To start I have read every thread that has mentioned this code. My specific symptoms haven't been mentioned as a whole, I have chased the problem and thrown a few parts at it but would like to see if anyone has any insight.

    A little history. 2001 330ci, 53,xxx when I purchased it four months ago, currently, 57,xxx. No issues were detected and the car ran perfectly for the first few weeks, SES first popped after about two weeks of driving. There were no obvious changes in the vehicle performance at first. Considering it was a garage queen the first thing I did was change the fuel filter and have the fuel system flushed.

    The SES has been intermittent but the cycle of being on has gotten longer as time went on. This led me to think initially that it was an O2 sensor going bad since it would fault and then go back to normal on its own. Periodically the engine will start to run as if it's missing a cylinder, doesn't happen very often though. All I have to do is turn the engine off and back on and it runs normally again. Sometimes the idle will be a little rough but this is intermittent as well, usually happens prior to the "missing" symptom.

    The fact that it's only one of the banks faulting led me to think that it wasn't a vacuum/air leak. I have all the usual suspect parts on the way as I type this. ICV grommet, DISA o-ring, SAI hose, both upper and lower intake boots, "F" connector and lots of vacuum line.

    As of right now, both O2 sensors have been replaced and the MAF as well, no love.

    If it was an air/vacuum leak wouldn't both banks be faulting or is it normal for only one side to fault?

    I know this is beating a dead horse but any insight is much appreciated.

  2. #2
    Join Date
    Jul 2011
    Location
    Arlington, VA
    Posts
    9,934
    My Cars
    2018 BMW M240i
    P0174 is a classic sign of vacuum leaks. At that age (yes, rubber and plastic parts wear with age) in betting there are several vacuum hoses that have a small leak. The ONLY way to find all leaks is to smoke test the intake. Try www.burms.org to find a shop that specializes in BMWs.

  3. #3
    Join Date
    Mar 2016
    Location
    Portland, OR
    Posts
    712
    My Cars
    2002 325Ci Cabriolet

  4. #4
    Join Date
    Nov 2017
    Location
    Morrisville, NC
    Posts
    6
    My Cars
    2001 330ci
    Quote Originally Posted by All2kool View Post
    Does the DISA pass a vacuum check?
    Just going to replace the o-ring to be sure, I don't know how to test it myself.

  5. #5
    Join Date
    Nov 2017
    Location
    Morrisville, NC
    Posts
    6
    My Cars
    2001 330ci
    Quote Originally Posted by MarcoZandrini View Post
    P0174 is a classic sign of vacuum leaks. At that age (yes, rubber and plastic parts wear with age) in betting there are several vacuum hoses that have a small leak. The ONLY way to find all leaks is to smoke test the intake. Try www.burms.org to find a shop that specializes in BMWs.
    Your link doesn't work.
    Last edited by e46user; 11-15-2017 at 01:48 PM.

  6. #6
    Join Date
    Jul 2011
    Location
    Arlington, VA
    Posts
    9,934
    My Cars
    2018 BMW M240i
    Ooops! www.bimrs.org.

  7. #7
    Join Date
    Mar 2016
    Location
    Portland, OR
    Posts
    712
    My Cars
    2002 325Ci Cabriolet
    Quote Originally Posted by e46user View Post
    Just going to replace the o-ring to be sure, I don't know how to test it myself.
    Simple: Remove the DISA. Close the flap. Place your finger over the small hole. Release the flap. The flap should stay closed until you remove your finger. A small amount of movement in the flap is acceptable but no more than just a tad really.

    Mine failed this test so it was replaced. Haven't seen a lean code since.

  8. #8
    Join Date
    Nov 2017
    Location
    Morrisville, NC
    Posts
    6
    My Cars
    2001 330ci
    Quote Originally Posted by All2kool View Post
    Simple: Remove the DISA. Close the flap. Place your finger over the small hole. Release the flap. The flap should stay closed until you remove your finger. A small amount of movement in the flap is acceptable but no more than just a tad really.

    Mine failed this test so it was replaced. Haven't seen a lean code since.
    Got it, thanks for the info I’ll give it a try.

  9. #9
    Join Date
    Mar 2016
    Location
    Portland, OR
    Posts
    712
    My Cars
    2002 325Ci Cabriolet
    Quote Originally Posted by e46user View Post
    Got it, thanks for the info I’ll give it a try.
    DISA rebuild kits are great but if you have a bad diaphragm, a rebuild will not fix that.

  10. #10
    Join Date
    Nov 2017
    Location
    Morrisville, NC
    Posts
    6
    My Cars
    2001 330ci
    Thanks again!

  11. #11
    Join Date
    Nov 2017
    Location
    Morrisville, NC
    Posts
    6
    My Cars
    2001 330ci
    Quote Originally Posted by All2kool View Post
    DISA rebuild kits are great but if you have a bad diaphragm, a rebuild will not fix that.
    Ok, thanks for the info I appreciate it.

  12. #12
    Join Date
    Jul 2017
    Location
    Usa
    Posts
    10
    My Cars
    E46 330i
    If you're removing the DISA, you should also consider replacing the seal. Silicone o-rings are available and make sure that the DISA isn't an issue.


    Sent from my iPhone using Tapatalk

  13. #13
    Join Date
    Dec 2016
    Location
    Cupertino, CA
    Posts
    10
    My Cars
    2001 BMW 325i
    That DISA valve is a pain. Given the age of your car, If it is original, it's probably bad. The diaphram usually gets weak, and cannot hold the valve.

    The one thing I've noticed about these valves is that your car can still run okay with it being somewhat bad, as long as you don't have any other small issues that can throw the intake out of wack.

    When I had this code, it was a combination of the DISA valve and and small hole in the intake hose.

  14. #14
    Join Date
    Jul 2011
    Location
    Arlington, VA
    Posts
    9,934
    My Cars
    2018 BMW M240i
    Quote Originally Posted by abrittis View Post
    That DISA valve is a pain. Given the age of your car, If it is original, it's probably bad. The diaphram usually gets weak, and cannot hold the valve.

    The one thing I've noticed about these valves is that your car can still run okay with it being somewhat bad, as long as you don't have any other small issues that can throw the intake out of wack.

    When I had this code, it was a combination of the DISA valve and and small hole in the intake hose.
    ^^^THIS^^^. The DISA gets sluggish over time. Also, the factory DISA has a metal pin in the flap that can come loose and get into the engine and cause major damage$. Repkace the DISA, but buy and install a German Auto Solutions o-ring.

  15. #15
    Join Date
    Mar 2016
    Location
    Portland, OR
    Posts
    712
    My Cars
    2002 325Ci Cabriolet
    Quote Originally Posted by MarcoZandrini View Post
    Repkace the DISA, but buy and install a German Auto Solutions o-ring.
    Replacing the DISA on an older car is a great idea but a new DISA will have a seal in place that should be used. Don't scrape off the seal the factory put on to install a new O-Ring.

Similar Threads

  1. intermittent electrical problems in E46 M3?
    By SDbboy in forum Car Audio & Electronics sponsored by Bavsound
    Replies: 2
    Last Post: 09-16-2008, 12:58 PM
  2. intermittent exhaust rattle
    By stealth M3 in forum 1992 - 1999 M3 (E36)
    Replies: 12
    Last Post: 09-08-2002, 10:42 PM
  3. Intermittent startup/ignition problems on 2001 M3 - HELP!!!
    By E46lsb in forum General BMW Mechanical Help sponsored by RM European Auto Parts
    Replies: 7
    Last Post: 07-01-2002, 02:49 PM
  4. Car shaking intermittently?
    By Lynch in forum General BMW and Automotive Discussion sponsored by Intercity Lines
    Replies: 3
    Last Post: 06-23-2002, 04:07 PM
  5. Program Intermittent wiper module???
    By BAADDOG in forum 1992 - 1999 M3 (E36)
    Replies: 7
    Last Post: 08-22-2001, 04:56 AM

Bookmarks

Posting Permissions

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