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M42 Engine Noise around 3000rpm

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    Originally posted by bmwman91 View Post
    Yeah, maybe it is the recording, but that M42 sounds normal. There was a slight "clanking" in your first video, at ~3500RPM. It sounded sort of like a loose catalytic converter core, or as Toaster said, something in the exhaust rubbing on the chassis.
    so i checked this again after running it and standing over the engine on the header/passenger side i can sort of hear the sound coming from down the header side/under the car.

    havent had a chance to have a buddy/gf help rev the engine while i was under the car but im starting to suspect a heat shield down there. ill try and update further.

    as for the oil leak im not sure where it is but the freshest looking oil is near the sensor down on the passenger side (crank posiiton sensor?). i don think the sensor is leaking but maybe something near there. the timing case is slathered in rtv from the previous owner so im guessing i just need to redo the gaskets and that should fix it. if it doesnt ive replaced about every gasket on the motor and i just wont worry about it. hopefully its not a cracked timing case.

    if anyone has any ideas for cleaning up the engine to pinpoint the leak other than tons of cans of degreaser lemme know. i might just take it to a detailer and let them figure it out


      Simple Green/Citrus Degreaser sprayed on heavy, agitated with a brush, rinsed off. Should do most of the grease, however, if it's caked on just use a scraper.

      Chances are that you have a timing case oil leak or a front crank seal issue.


        can someone direct me to a comprehensive list of things I should change if I dive into the timing cover? mainly since I started digging though real OEM and just want to know all the good things to do while I'm in there

        things I don't need:
        timing chain
        timing chain tensioner
        exhaust and intake cam sprockets

        everything else I don't know the condition of and I'm trying to get this bad boy where I won't need to open it up again any time soon. water pump? idler sprocket? thermostat? certain bolts?

        I briefly looked into timing case updating to the newer style but sourcing everything and potentially having to do the inner side seems like more work than I'd like


          Idler sprocket, crank sprocket, crank seal, profile gasket (but only if it looks bad), guides if you want to keep it basic. The WP/thermostat aren't bad to replace at a later date.


            Doesn't look like anyone has mentioned the metal shield thing on the side of the engine over the exhaust manifold that runs under the ignition wires. One of the tabs broke off mine and it rattled pretty good.

            Alpine II 318is


              Sladek did you ever figure out the rattle issue for sure? I'm having the exact same thing right now and would love to know what your solution was so I can start there!
              Steve Toronto
              1991 318is Brillantrot
              Build Thread


                Start tapping things until you find the issue.

                This past week I had a rattle I couldn't figure out until I tapped the collector ahead of the catalyst, and I discovered that the oxygen sensor element had come loose, but remained within the cage.