Video-What is this sound?

Collapse
X
Collapse
 
  • Page of 2
  • Filter
  • Time
  • Show
Clear All
new posts
Previous 1 2 template Next
  • rpowers
    Senior Member
    • Oct 2007
    • 304
    #1

    Video-What is this sound?

    I've noticed a very annoying (and hopefully not potentially damaging) sound that only occurs when the engine is under high load (1800+rpm).

    Here is the link to a short YouTube video: http://www.youtube.com/watch?v=B_TuVy6gwYA

    It sounds like maybe a valve tappet slapping, but it seems too loud for that.

    If it is a valve gap slapping, why does it only happen under heavy load?

    If not a valve slap sound, what else could it be? Something in the drive train?

    Thanks, and enjoy my artistic video skills...

    -Rick
    Last edited by rpowers; 03-18-2011, 10:03 AM.
    Tags: None
  • ndutton
    Afourian MVP
    • May 2009
    • 9776
    #2
    Might be a valve out of adjustment. Might also be a weak spark in one cylinder (plug, plug wire, distributor cap).

    Do I hear an exhaust leak ahead of the mixer?
    Neil
    1977 Catalina 30
    San Pedro, California
    prior boats 1987 Westsail 32, 1970 Catalina 22
    Had my hands in a few others

    Comment

    • rpowers
      Senior Member
      • Oct 2007
      • 304
      #3
      No exhaust leak

      ...just replaced the manifold gasket (see stud replacement thread) so no leak there...

      Comment

      • jpian0923
        Afourian MVP
        • Sep 2010
        • 994
        #4
        Sounds like valves but I just want to make one comment about the fact that you posted a video. . . A picture is worth a thousand words, a video is priceless!

        Instead of taking 20 posts to get to the bottom of this problem it took one!

        Everyone should be posting video and or pictures of their problems and I think most problems can be solved more quickly. Just my two cents.
        "Jim"
        S/V "Ahoi"
        1967 Islander 29
        Harbor Island, San Diego
        2/7/67 A4 Engine Block date

        Comment

        • domenic
          Senior Member
          • Jul 2010
          • 469
          #5
          Originally posted by rpowers View Post
          I've noticed a very annoying (an hopefully not potentially damaging) sound that only occurs when the engine is under high load (1800+rpm).

          Here is the link to a short YouTube video: http://www.youtube.com/watch?v=B_TuVy6gwYA

          It sounds like maybe a valve tappet slapping, but it seems too loud for that.

          If it is a valve gap slapping, why does it only happen under heavy load?

          If not a valve slap sound, what else could it be? Something in the drive train?

          Thanks, and enjoy my artistic video skills...

          -Rick
          Rick, your sound is not like mine. Mine is more of a ticking(light clanking.)


          Check the plug wires over the plugs.

          Comment

          • smaarch
            Senior Member
            • Jul 2008
            • 47
            #6
            hahaha
            reminds me of bob dylan's subterranean homesick blues

            Comment

            • rpowers
              Senior Member
              • Oct 2007
              • 304
              #7
              Valves

              Ok, so a leading hypothesis is valves. (any second possibilities?)

              I'm down with that, and plan on checking the clearances this weekend.

              But why would the sound occur only when under load?

              -Rick

              Comment

              • BryanLee
                Senior Member
                • Jun 2008
                • 72
                #8
                I have no idea what it is, but just wanted to add I like the video! It would be great to get a library of videos with odd sounds and a final diagnosis for reference. I watched the video, just so once you find out what it is, if I hear the noise I will know where to start looking.

                Thanks!
                Bryan

                Comment

                • ndutton
                  Afourian MVP
                  • May 2009
                  • 9776
                  #9
                  I have a question on the background noise, what's assumed to be normal engine running sounds.

                  I'm not saying the sounds beyond the clacking in question are normal or not but they are certainly way different than mine. That's why I asked about an exhaust leak in my previous post. Maybe what I'm hearing is normal (comments?) or seemingly amplified due to the audio component of the video recording equipment but listening to it I can't believe we have the same engine!

                  I've had comments from slip neighbors walking by when I've been running my engine at the slip and water is batching out the exhaust, "Is your engine running? Man, I can't even hear it!" I've always thought it was because most sailboats in our area are diesel powered and we know how they sound.

                  And smell.
                  Neil
                  1977 Catalina 30
                  San Pedro, California
                  prior boats 1987 Westsail 32, 1970 Catalina 22
                  Had my hands in a few others

                  Comment

                  • rpowers
                    Senior Member
                    • Oct 2007
                    • 304
                    #10
                    Background Noise

                    Perhaps amplified due to the engine hatch opening.

                    When the engine is closed up and idling, same thing, very quiet, with water pouring out the back.

                    Comment

                    • edwardc
                      Afourian MVP
                      • Aug 2009
                      • 2511
                      #11
                      I too had some concern about the lower-pitched sound in the "high load" section. The first thought I had was of Shawn's shaft rubbing on his shaft tube. Could there be an alignment issue here?
                      @(^.^)@ Ed
                      1977 Pearson P-323 "Dolce Vita"
                      with rebuilt Atomic-4

                      sigpic

                      Comment

                      • ndutton
                        Afourian MVP
                        • May 2009
                        • 9776
                        #12
                        Rick, I gotta say even with the engine compartment open it doesn't sound like that.
                        Neil
                        1977 Catalina 30
                        San Pedro, California
                        prior boats 1987 Westsail 32, 1970 Catalina 22
                        Had my hands in a few others

                        Comment

                        • JOHN COOKSON
                          Afourian MVP, Professor Emeritus
                          • Nov 2008
                          • 3501
                          #13
                          Do you hear the same noise in reverse under high load?

                          TRUE GRIT
                          Try disconnecting one spark plug at a time while making the noise to see if it is a paticular cylinder.
                          Last edited by JOHN COOKSON; 03-18-2011, 12:23 PM. Reason: One more idea

                          Comment

                          • Bobgrif
                            Frequent Contributor
                            • Aug 2010
                            • 8
                            #14
                            I unfortunately cannot watch the video (firewall blocks it!), but I'm surprised no-one has mentioned piston slap which is caused by a worn cylinder and rings, and only manifests itself when the engine is under load. If it is piston slap, only cure is a rebore and new pistons/rings.

                            Bob (sv 'Dovetale', C&C Corvette, Ontario, Canada)

                            Comment

                            • Dromo
                              Senior Member
                              • Mar 2008
                              • 217
                              #15
                              Idler gear?

                              Rick , I would agee with ndutton that it sounds like an exhaust leak.
                              When you check the valves and If they are OK , it might be the idler gear and if I remember correctly it's nothing to be concerned about
                              Good Luck Rick

                              Comment

                              Previous 1 2 template Next
                              Working...
                              X