Can a bad injector sound like a loose valve idle?
4BTSwaps.com is the premier Cummins Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 4 of 4

Thread: Can a bad injector sound like a loose valve idle?

  1. #1
    Supporting Member
    Join Date
    Apr 2010
    Location
    el segundo
    Posts
    241
    Thanks
    1
    Thanked 1 Time in 1 Post

    Default Can a bad injector sound like a loose valve at idle?

    My 4BD2tc has what I thought was a rocker arm a little loose. At idle it sounds just like a really loose valve, but as soon as you increase the RPM's it goes away. It sounds like just one cylinder also. One of the center ones, likely the rear of the two. I don't have any smoke to speak of, idle is pretty smooth too.

    Thinking valves, I adjusted all the valves to factory specs and it's the same sound. I checked the valves again the next morning to make sure they dead cold...All in spec.!

    I have heard talk of a diesel knock from bad injectors and searched Google. I found a bad injector can make a similar sound.

    I am going to the injector shop tomorrow and let them listen to it and get their idea's.

    What do you guy's think?

    Thanks

    Doug
    Last edited by doug720; 01-11-2011 at 10:43 PM.

  2. Remove Advertisements
    4BTSwaps.com
    Advertisements
     

  3. #2
    Registered User
    Join Date
    Aug 2010
    Location
    Miami, Florida
    Posts
    41
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    Sounds like a lack of fuel. One cylinder running lean because of an underperforming injector sounds about right. I have the same condition on one of my 2009 NRR's. Usually it sounds like marbles in a can.

    Does it only make the noise cold and go away when it warms up?

  4. #3
    Supporting Member
    Join Date
    Apr 2010
    Location
    el segundo
    Posts
    241
    Thanks
    1
    Thanked 1 Time in 1 Post

    Default

    The injector shop thinks I have a bad lifter! They loosened the fuel pipe to each injector and the idle dropped, but the sound stayed the same. Not good.

    New question, anyone experienced a bad lifter?

    Doug

  5. #4
    New Registered User
    Join Date
    Dec 2012
    Location
    EAST TN.
    Posts
    4
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Default

    I know this is an old thread, but the symptoms that sunbiodiesel mentioned is what is happening to my engine. I am new to diesel engines and just bought a 4bt and noticed a noise from the rear valve cover that sounded like a lifter ticking at startup but would start going away as it warmed up. I checked the valve lash on all the valves and they were all good. Does anyone have any idea?

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Posting Permissions

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