Loud metal clash while driving, no longer starts

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  • Chilezen
    E30 Mastermind
    • Dec 2013
    • 1881

    #1

    Loud metal clash while driving, no longer starts

    Video of attempted start

    Turns over, doesn't fire. There does seem to be a faint knocking sound on the bottom end.

    I was driving normally, accelerating from a stop, and without warning I hear a loud metal-being-annihilated clash. It was similar in nature to grinding gears, but lower pitched. I coast to a stop and push it to a parking lot. Towed home.

    There are no leaks, no fumes, no external damage within the engine bay.

    Previously, for several months, this car would stall at idle and cut out during acceleration (but continue running). I don't drive it often for that reason. But otherwise it runs fine.

    The timing belt is new and fine, it still rotates the cam. This leads me to believe the valves didn't hit.

    I can't mentally piece together the loud sound with the car not starting, given that I hear no clashing sound during the attempt to start it. I don't understand why the engine still turns over if there *is* metal broken. And if there isn't metal broken, why won't it start?

    Currently building a badass coffee table
    Random stuff on insta @kevanromero
  • ahlem
    Grease Monkey
    • Sep 2008
    • 369

    #2
    What do you see when you take off the valve cover? I'm guessing you broke your timing belt. You can pull the rubber cover off the front of the drivers side of the motor and look for rubber teeth.

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    • Chilezen
      E30 Mastermind
      • Dec 2013
      • 1881

      #3
      Originally posted by Chilezen
      The timing belt is new and fine, it still rotates the cam. This leads me to believe the valves didn't hit.
      I haven't taken off the valve cover yet.

      Currently building a badass coffee table
      Random stuff on insta @kevanromero

      Comment

      • 15Michaeljoseph
        E30 Mastermind
        • Aug 2013
        • 1693

        #4
        Originally posted by ahlem
        What do you see when you take off the valve cover? I'm guessing you broke your timing belt. You can pull the rubber cover off the front of the drivers side of the motor and look for rubber teeth.
        +1 although when mine went it wasn't really metallic sounding, but you could hear the thwacks as the valves hit, really fast. that 'oh sheit' moment every e30 owner fears.


        --Mike
        (OO=[][]=OO) For Life

        Comment

        • AndrewBird
          The Mad Scientist
          • Oct 2003
          • 11892

          #5
          Pull the dip stick and see what the oil looks like and report back.

          Comment

          • vpilarrt
            R3VLimited
            • Jun 2006
            • 2096

            #6
            Quote:
            Originally Posted by Chilezen
            The timing belt is new and fine, it still rotates the cam. This leads me to believe the valves didn't hit.

            I haven't taken off the valve cover yet.
            So how do you know that the cam still rotates?

            Comment

            • Chilezen
              E30 Mastermind
              • Dec 2013
              • 1881

              #7
              Originally posted by vpilarrt
              So how do you know that the cam still rotates?
              I have now pulled off the cover, the cam does indeed rotate:



              The oil on the stick looks clean, I changed it about a month ago.

              A compression test is next.

              Currently building a badass coffee table
              Random stuff on insta @kevanromero

              Comment

              • Chilezen
                E30 Mastermind
                • Dec 2013
                • 1881

                #8
                Update:


                Currently building a badass coffee table
                Random stuff on insta @kevanromero

                Comment

                • econti
                  E30 Enthusiast
                  • May 2014
                  • 1090

                  #9
                  that's an issue
                  sigpic

                  (clicky on piccy to get to thread)

                  Comment

                  • AndrewBird
                    The Mad Scientist
                    • Oct 2003
                    • 11892

                    #10
                    You have at least one broken valve.

                    Ouch.

                    Pray it didn't take out a piston as well.

                    Comment

                    • Chilezen
                      E30 Mastermind
                      • Dec 2013
                      • 1881

                      #11
                      Cylinder 6 has no compression (I wonder why...). The rest are fine.

                      How can I check the valves? I can visibly see the rockers moving those valves.

                      --

                      Sooo, what do I do? I spent $2k on the rebuild only 1,000 miles ago.

                      Currently building a badass coffee table
                      Random stuff on insta @kevanromero

                      Comment

                      • mr.vang
                        R3V Elite
                        • May 2010
                        • 4371

                        #12
                        Time for s52 swap
                        Bought parts from me before? leave your feedback here

                        Comment

                        • Chilezen
                          E30 Mastermind
                          • Dec 2013
                          • 1881

                          #13
                          Originally posted by Chilezen
                          How can I check the valves?
                          The exhaust valve is still pressing against the rocker, even though the cam lobe is on the other side. It's as if the keepers aren't keeping it down.

                          I have no money for any swap or another rebuild. If the valve is the only problem, I may have enough $ (in time) to replace it, assuming the piston and cylinder wall is intact.

                          Currently building a badass coffee table
                          Random stuff on insta @kevanromero

                          Comment

                          • smooth
                            E30 Mastermind
                            • Apr 2005
                            • 1940

                            #14
                            Originally posted by Chilezen
                            Sooo, what do I do? I spent $2k on the rebuild only 1,000 miles ago.
                            Call the person who did the rebuild.
                            Das ist nicht nur nicht richtig, es ist nicht einmal falsch!

                            Comment

                            • Chilezen
                              E30 Mastermind
                              • Dec 2013
                              • 1881

                              #15
                              Originally posted by smooth
                              Call the person who did the rebuild.
                              Thanks for the suggestion, but as you'll see in my sig, I did the rebuild.

                              Currently building a badass coffee table
                              Random stuff on insta @kevanromero

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