can I start my M20 engine with the valve cover off?

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  • HardTech
    Advanced Member
    • Dec 2007
    • 174

    #1

    can I start my M20 engine with the valve cover off?

    There's a loud ticking coming from one of the valves, and hearing the valves with the valve cover off would help.
  • Number dude
    Noobie
    • Oct 2008
    • 18

    #2
    Likely when you remove your valve cover, you'll find a broken rocker arm. If you don't, read a how-to on valve lash adjustment. If that doesn't work, you might have an oiling issue.

    But to answer your main question, you can start an engine with the valve cover off, just expect it to get slightly messy.

    Comment

    • SamE30e
      R3V Elite
      • Sep 2007
      • 4319

      #3
      very very messy.
      1985 325e 2.8 Turbo VEMS

      Comment

      • HardTech
        Advanced Member
        • Dec 2007
        • 174

        #4
        Originally posted by Number dude
        Likely when you remove your valve cover, you'll find a broken rocker arm. If you don't, read a how-to on valve lash adjustment. If that doesn't work, you might have an oiling issue.

        But to answer your main question, you can start an engine with the valve cover off, just expect it to get slightly messy.
        one of the rocker arms is loose (it wiggles from side to side) and it's hard to accurately adjust that valve. Plus, I notice there's oil in that cylinder (spark plug has oil on it).

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        • scabzzzz
          Estado de mierda de encargo
          • Jul 2007
          • 6870

          #5
          Id start by adjusting that valve.
          The car would barely run with the valve cover off and it would be really fucking messy.

          Comment

          • TwoJ's
            R3V Elite
            • Oct 2005
            • 4908

            #6
            Originally posted by HardTech
            one of the rocker arms is loose (it wiggles from side to side) and it's hard to accurately adjust that valve. Plus, I notice there's oil in that cylinder (spark plug has oil on it).
            Get a new retainer for that valve, or for all of them. Rocker arm shouldn't be loose.

            Sounds like a ratty m20 though.

            Comment

            • HardTech
              Advanced Member
              • Dec 2007
              • 174

              #7
              Originally posted by scabzzzz
              Id start by adjusting that valve.
              The car would barely run with the valve cover off and it would be really fucking messy.
              well, the car was a little loud last week, but I did a valve adjustment and it became a lot louder (adjusted to .011", .279mm stone cold). The next day, I did another valve adjustment (adjusted to .010", .249mm stone cold). It became a little quieter, but it's still a lot louder than what it was before.

              I guess running the car with the valve cover off isn't a good idea

              Comment

              • HardTech
                Advanced Member
                • Dec 2007
                • 174

                #8
                Originally posted by TwoJ's
                Get a new retainer for that valve, or for all of them. Rocker arm shouldn't be loose.

                Sounds like a ratty m20 though.
                is this the retainer?



                edit: it's a m20b27 from a 325es with 151k miles. It runs fine, but it leaks a little more than I'd like, and the valves are really loud.
                Last edited by HardTech; 10-20-2008, 10:52 AM.

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                • Number dude
                  Noobie
                  • Oct 2008
                  • 18

                  #9
                  Originally posted by scabzzzz
                  Id start by adjusting that valve.
                  The car would barely run with the valve cover off and it would be really fucking messy.
                  It'd run fine, but the PCV will be open (the breather for the valve cover). I can't remember where in the intake tract it runs to but it could either idle the car high or it could chuck badly. Basically if you start it with the valve cover removed, plug that hose that runs to the intake tract.

                  And expect a mess...i wouldn't start it without the valve cover, but it can be done.

                  If the rocker arms move side to side, like said above, get new retainers, they shouldn't do that. Just a very slight up and down.

                  Be sure to retighten them to specs also so they don't work lose and you don't risk overtightening and breaking something.

                  Comment

                  • HardTech
                    Advanced Member
                    • Dec 2007
                    • 174

                    #10
                    Originally posted by Number dude
                    It'd run fine, but the PCV will be open (the breather for the valve cover). I can't remember where in the intake tract it runs to but it could either idle the car high or it could chuck badly. Basically if you start it with the valve cover removed, plug that hose that runs to the intake tract.

                    And expect a mess...i wouldn't start it without the valve cover, but it can be done.

                    If the rocker arms move side to side, like said above, get new retainers, they shouldn't do that. Just a very slight up and down.

                    Be sure to retighten them to specs also so they don't work lose and you don't risk overtightening and breaking something.
                    gotcha

                    Terre Haute? You go to Rose Hulman?

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                    • Number dude
                      Noobie
                      • Oct 2008
                      • 18

                      #11
                      Negative, Ivy Tech for me. :(

                      Comment

                      • HardTech
                        Advanced Member
                        • Dec 2007
                        • 174

                        #12
                        Originally posted by Number dude
                        Negative, Ivy Tech for me. :(

                        Also, it'd be the chucking the car badly thing, it clicked how the system was ran. Been a long time since i've had my e30's engine together.
                        can you reword that last part? It's a little unclear.

                        Comment

                        • Number dude
                          Noobie
                          • Oct 2008
                          • 18

                          #13
                          Originally posted by HardTech
                          can you reword that last part? It's a little unclear.
                          Nevermind, i just took it out and hoped you wouldn't have seen it, lol. It's a long explanation of how it works.

                          Basically with that open it'll make the car want to run really rough (maybe not at all, some cars act different) is all you need to know. :) Start your car with the oil cap off for a similar effect.

                          Comment

                          • HardTech
                            Advanced Member
                            • Dec 2007
                            • 174

                            #14
                            Originally posted by Number dude
                            Nevermind, i just took it out and hoped you wouldn't have seen it, lol. It's a long explanation of how it works.

                            Basically with that open it'll make the car want to run really rough (maybe not at all, some cars act different) is all you need to know. :) Start your car with the oil cap off for a similar effect.
                            ok.. I'll not risk it. It was kind of a last resort anyway, since I don't want the valve to suddenly break and shoot out at me.

                            Comment

                            • Number dude
                              Noobie
                              • Oct 2008
                              • 18

                              #15
                              I meant the PCV line open, not the valve cover, you'd be fine with the line plugged and the cover open. But i'd avoid doing it and look elsewhere for the problem and i think you found the problem in the retainers.

                              I suck at explaining things.

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