Announcement

Collapse
No announcement yet.

Random screech that occurs intermittently

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • [Non Corsa] Random screech that occurs intermittently

    My MX5 has developed a random screech.

    Bit of background: recently changed the cam belt, pulleys, water pump and a few other bits and pieces that are part and parcel of the job (documented here). Covered about 40 miles of trouble free motoring but driving the car last night I got this screech. Seems to happen occasionally on start up and occasionally on down shifting. Video compilation below provided in the link below. You'll hear on the 3rd clip when I lightly revved the car after first starting it, it made a horrible crunching sound - really have no idea what that could have been and has only done it the once. Car is driving absolutely fine with no other adverse effects.



    Any ideas?

    Thanks.
    [URL="https://www.thecorsa.co.uk/forum/classified-ads/parts-for-sale/1043-big-clear-out-exhaust-suspension-etc"][B][COLOR="#0000CD"]Big clear out of parts[/COLOR][/B][/URL]
    [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/732-sunny-melon-le-1-3-cdti"][B][COLOR="#0000cd"]Corsa D Yellow LE[/COLOR][/B][/URL]
    [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/225-atlantis-blue-5-door"][B][COLOR="#0000cd"]Corsa B Atlantis Blue[/COLOR][/B][/URL]
    [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/1301-1993-mazda-eunos-roadster"][B][COLOR="#006400"]Mazda Eunos V-Spec[/COLOR][/B][/URL]

  • #2
    I'd probably be looking at the bearings in all of the pulleys you've replaced. I don't know the setup of the MX5 whatsoever, but any idler or tensioner pulleys? Perhaps overtensioned causing the bearings to breakup/fail.

    Did you replace a drive belt? Or just the cam belt and other things driven by the cam belt?
    |> Spec2 R33 Skyline GTS-T <|

    Comment


    • #3
      Everything was torqued up to specification so I'd be surprised if it was any of the pulley bearings.

      Alternator belt and PAS belt were changed too. No signs of abnormal wear or grease on them. They both feel appropriately tensioned and have no signs of glazing.
      [URL="https://www.thecorsa.co.uk/forum/classified-ads/parts-for-sale/1043-big-clear-out-exhaust-suspension-etc"][B][COLOR="#0000CD"]Big clear out of parts[/COLOR][/B][/URL]
      [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/732-sunny-melon-le-1-3-cdti"][B][COLOR="#0000cd"]Corsa D Yellow LE[/COLOR][/B][/URL]
      [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/225-atlantis-blue-5-door"][B][COLOR="#0000cd"]Corsa B Atlantis Blue[/COLOR][/B][/URL]
      [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/1301-1993-mazda-eunos-roadster"][B][COLOR="#006400"]Mazda Eunos V-Spec[/COLOR][/B][/URL]

      Comment


      • #4
        Pictures of the setup in my project thread, linked to above in the first post.
        [URL="https://www.thecorsa.co.uk/forum/classified-ads/parts-for-sale/1043-big-clear-out-exhaust-suspension-etc"][B][COLOR="#0000CD"]Big clear out of parts[/COLOR][/B][/URL]
        [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/732-sunny-melon-le-1-3-cdti"][B][COLOR="#0000cd"]Corsa D Yellow LE[/COLOR][/B][/URL]
        [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/225-atlantis-blue-5-door"][B][COLOR="#0000cd"]Corsa B Atlantis Blue[/COLOR][/B][/URL]
        [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/1301-1993-mazda-eunos-roadster"][B][COLOR="#006400"]Mazda Eunos V-Spec[/COLOR][/B][/URL]

        Comment


        • #5
          Chuck some talc on the aux belt - see if that stops it. A screech on startup and downshifts is often a belt slipping slightly. Could just be that the new belt has stretched a wee bit, depends how they are tensioned.

          A waterpump bearing will make almost the exact same noise, but usually it's the belt.
          1972 Viva restoration thread - http://www.thecorsa.co.uk/projects-b....html#post1534

          Comment


          • #6
            Water pump was replaced with a genuine oem one so I'd be amazed if it was the pump.

            My first thought was definitely belts too, just sounds a bit different to the typical alternator belt squeel.

            I have read that you should recheck the tension of the altenator and power steering belts after a hundred miles or so as they bed in, so hopefully it's just that. The alternator belt was an aftermarket part that didn't look like it was sitting perfectly flush with the pulleys when originally fitted, so perhaps now it's bedded in it is sitting better in the pulleys, resulting in it becoming a bit slacker.

            Still bemused by the crunch sound. Only happened the once. Closest thing I can compare that to is a bad gear change, but the car was in neutral.
            [URL="https://www.thecorsa.co.uk/forum/classified-ads/parts-for-sale/1043-big-clear-out-exhaust-suspension-etc"][B][COLOR="#0000CD"]Big clear out of parts[/COLOR][/B][/URL]
            [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/732-sunny-melon-le-1-3-cdti"][B][COLOR="#0000cd"]Corsa D Yellow LE[/COLOR][/B][/URL]
            [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/225-atlantis-blue-5-door"][B][COLOR="#0000cd"]Corsa B Atlantis Blue[/COLOR][/B][/URL]
            [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/1301-1993-mazda-eunos-roadster"][B][COLOR="#006400"]Mazda Eunos V-Spec[/COLOR][/B][/URL]

            Comment


            • #7
              I thought you'd replaced the pump, so that's unlikely.

              It doesn't sound quite as high pitched as a slipping belt usually does, but it's hard to tell from a video clip. I'd check that aux belt, it only takes a fraction of bedding in for them to loosen enough to slip a bit.
              1972 Viva restoration thread - http://www.thecorsa.co.uk/projects-b....html#post1534

              Comment


              • #8
                Was running late this morning so drove to work instead of cycling.



                Car is driving absolutely 100%, so whatever is causing the sound isn't doing any apparent harm to anything else.



                On the drive in it only made the sound once, and only slightly. Before setting off I checked the tension of the alternator and PAS belts and admittedly the alternator belt did feel slacker than it was when I fitted it a couple of weeks ago. I'll retension it at some point over the next couple of days and report back with what difference (if any) it makes.



                I agree with you Taurus that it doesn't completely sound like a conventional loose belt squeel, but it's a starting point at least.
                [URL="https://www.thecorsa.co.uk/forum/classified-ads/parts-for-sale/1043-big-clear-out-exhaust-suspension-etc"][B][COLOR="#0000CD"]Big clear out of parts[/COLOR][/B][/URL]
                [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/732-sunny-melon-le-1-3-cdti"][B][COLOR="#0000cd"]Corsa D Yellow LE[/COLOR][/B][/URL]
                [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/225-atlantis-blue-5-door"][B][COLOR="#0000cd"]Corsa B Atlantis Blue[/COLOR][/B][/URL]
                [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/1301-1993-mazda-eunos-roadster"][B][COLOR="#006400"]Mazda Eunos V-Spec[/COLOR][/B][/URL]

                Comment


                • #9
                  Any cats missing in the neighbourhood?

                  Comment


                  • #10
                    Haha not that I'm aware of.

                    Just been out to properly check the belt tensions. PAS belt is fine but the alternator belt was far slacker than I realised. Surprised at how quickly it has bedded in! Only covered about 40 miles before the screech first happened.

                    Retensioned it but haven't been for a drive yet. I'd be surprised if it hasn't sorted it though - remaining optimistic anyway lol.
                    [URL="https://www.thecorsa.co.uk/forum/classified-ads/parts-for-sale/1043-big-clear-out-exhaust-suspension-etc"][B][COLOR="#0000CD"]Big clear out of parts[/COLOR][/B][/URL]
                    [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/732-sunny-melon-le-1-3-cdti"][B][COLOR="#0000cd"]Corsa D Yellow LE[/COLOR][/B][/URL]
                    [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/225-atlantis-blue-5-door"][B][COLOR="#0000cd"]Corsa B Atlantis Blue[/COLOR][/B][/URL]
                    [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/1301-1993-mazda-eunos-roadster"][B][COLOR="#006400"]Mazda Eunos V-Spec[/COLOR][/B][/URL]

                    Comment


                    • #11
                      Drove to work and back today and no hint of a squeel. Retensioning the alternator belt seems to have done the trick. Just confused me as it didn't sound like a conventional loose belt squeel. Ahh well
                      [URL="https://www.thecorsa.co.uk/forum/classified-ads/parts-for-sale/1043-big-clear-out-exhaust-suspension-etc"][B][COLOR="#0000CD"]Big clear out of parts[/COLOR][/B][/URL]
                      [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/732-sunny-melon-le-1-3-cdti"][B][COLOR="#0000cd"]Corsa D Yellow LE[/COLOR][/B][/URL]
                      [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/225-atlantis-blue-5-door"][B][COLOR="#0000cd"]Corsa B Atlantis Blue[/COLOR][/B][/URL]
                      [URL="https://www.thecorsa.co.uk/forum/general-discussion/car-chat/projects-builds/1301-1993-mazda-eunos-roadster"][B][COLOR="#006400"]Mazda Eunos V-Spec[/COLOR][/B][/URL]

                      Comment


                      • #12
                        Probably because it's squealing with a Japanese accent.
                        1972 Viva restoration thread - http://www.thecorsa.co.uk/projects-b....html#post1534

                        Comment


                        • #13
                          I still think it was a cat! But they will always deny it. ( "Me?How?" )

                          Comment


                          • #14
                            |> Spec2 R33 Skyline GTS-T <|

                            Comment

                            Working...
                            X