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    Front Crank Seal?

    I found a new oil leak on the cabrio. It's marked with an arrow in the picture below. Front crank seal? If can do further investigation if it makes a difference for diagnosis, but it seems to leak when the engine is running but not when it just sits. Thanks, Cory

    Oil Leak by cory58f5, on Flickr
    1992 325i Cabrio
    1988 320i Touring
    2000 M5
    1977 530i
    2015 328i - Euro Delivery/Performance Center Delivery
    BMWCCA
    E30CCA

    #2
    degrease it and above that area there to isolate whether it is starting/coming from as it might be starting from above the seal. If its the seal it will start at the lip that's near the vibration damper
    89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

    new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

    Comment


      #3
      Originally posted by digger View Post
      degrease it and above that area there to isolate whether it is starting/coming from as it might be starting from above the seal. If its the seal it will start at the lip that's near the vibration damper
      Thank you. It's definitely running in that area from the front lip back. Good advice - I will check above there again for signs of a leak.
      1992 325i Cabrio
      1988 320i Touring
      2000 M5
      1977 530i
      2015 328i - Euro Delivery/Performance Center Delivery
      BMWCCA
      E30CCA

      Comment


        #4
        Why would you guess?
        Replace both seals if you have to unscrew the crankshaft bolt.

        There is nothing else in that area unless the oil drips from the head.

        Comment


          #5
          I spot an oil drip on the far left of your photo on one of the oil pan bolts....

          The front main was nice and easy to do when i had the engine out of the car. wouldn't be much fun with it in the car though.

          I am a big porponent of "dont touch what isnt leaking" when it comes to lip seals. So if the other lip seal on the oil pump drive shaft isnt leaking and looks good, id be inclined not to touch it...Although thats a tough call given how much of a pain in the ass it is to change those lip seals. But you'd hate to repalce a non leaking seal only for your new one to leak a week later.

          Comment


            #6
            Whenever I do timing belts on these cars I do all the seals. Intermediate, Crank, Cam, and the lower housing to block. They are all old probably due...
            Last edited by moatilliatta; 11-10-2021, 06:37 AM.

            I was up above it, Now I'm down in it ~ Entropy - A Build thread.

            Comment


              #7
              I suspect the piece that hold the crank and intermediate seals attached to the block (don't know what they call it) it has a gasket that might leak.

              Comment


                #8
                Thanks again for all the replies! Without taking things apart, I cannot see any leak above the crank, so I'll plan to replace all 3 seals and cover gasket "while I'm in there." Since this will be the first time I remove the timing belt myself, I have a couple of follow-up questions.

                1. I just had the timing belt done in July. The Bentley manual says to replace it anytime the tension is relieved Would you all replace it again so soon just because it's removed?
                2. Do I need a tool to keep the engine at TDC? Does that tool even exist?

                Thanks again,

                Cory
                1992 325i Cabrio
                1988 320i Touring
                2000 M5
                1977 530i
                2015 328i - Euro Delivery/Performance Center Delivery
                BMWCCA
                E30CCA

                Comment


                  #9
                  I would replace belt as it’s cheap but tensioner will be ok. There is no tool for tdc Line OT mark on vibration damper ( or crank gear) with notch on the lower timing cover and the cam gear should align with mark on head. You may need a tool to hold crank gear to get big crank bolt loose if using a breaker . Leave timing belt on until you break cam bolt, intermediary gear bolt and crank bolt loose so the engine doesn’t go out of time.
                  89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

                  new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

                  Comment


                    #10
                    Originally posted by digger View Post
                    I would replace belt as it’s cheap but tensioner will be ok. There is no tool for tdc Line OT mark on vibration damper ( or crank gear) with notch on the lower timing cover and the cam gear should align with mark on head. You may need a tool to hold crank gear to get big crank bolt loose if using a breaker . Leave timing belt on until you break cam bolt, intermediary gear bolt and crank bolt loose so the engine doesn’t go out of time.
                    Thank you! Great advice. Is it ok to use an impact to break those bolts loose?
                    1992 325i Cabrio
                    1988 320i Touring
                    2000 M5
                    1977 530i
                    2015 328i - Euro Delivery/Performance Center Delivery
                    BMWCCA
                    E30CCA

                    Comment


                      #11
                      Originally posted by cory58 View Post

                      Thank you! Great advice. Is it ok to use an impact to break those bolts loose?
                      You can't use it in that area.

                      You'd better buy a crankshaft holding tool and new bolts for it.
                      https://www.ebay.com/itm/143489251994

                      and a pipe to make an extension for a breaker bar.

                      ---
                      While the timing belt is still on, loosen the bolts using the belt to keep them from rotating. You'll have to replace it anyway.
                      Last edited by Vincenze; 11-15-2021, 12:08 PM.

                      Comment


                        #12
                        Originally posted by Vincenze View Post

                        You can't use it in that area.

                        You'd better buy a crankshaft holding tool and new bolts for it.
                        https://www.ebay.com/itm/143489251994

                        and a pipe to make an extension for a breaker bar.

                        ---
                        While the timing belt is still on, loosen the bolts using the belt to keep them from rotating. You'll have to replace it anyway.
                        Thank you Vincenze . Very helpful info. I figured I would need a tool to hold the crank but had not started looking yet. Regarding the impact wrench, do you mean it won't fit in that area or it should not be used on the crank bolt? Coincidentally, there is a thread on the R3v FB page today about breaking loose the crank bolt. Here is a link to the conversation.

                        https://www.facebook.com/photo/?fbid...61557919832627

                        Cory
                        1992 325i Cabrio
                        1988 320i Touring
                        2000 M5
                        1977 530i
                        2015 328i - Euro Delivery/Performance Center Delivery
                        BMWCCA
                        E30CCA

                        Comment


                          #13
                          Originally posted by cory58 View Post
                          do you mean it won't fit in that area or it should not be used on the crank bolt?
                          The radiator support is in front of the bolt. I don't think you'll be able to insert a regular impact wrench there.

                          And it shouldn't be used on a crankshaft anyway. The bearings can be destroyed. Of course, every auto mechanic uses it.

                          The tool isn't expensive considering the power you need to unscrew the bolt and then screw it back.

                          Comment


                            #14
                            If the pan is off a piece of timber jammed inside between crank and block skirt also works well
                            89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

                            new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

                            Comment


                              #15
                              So I've decided to replace all 3 seals "while I'm in there," regardless of which one is leaking. Coincidentally, my favorite YouTube channel (M539 Restorations) recently did a timing belt job on an early M20 E30, including the cam seal. There was an o-ring on the cam seal cover that he also replaced. I can't find that o-ring on any of the RealOEM diagrams for my car. Did the design change and eliminate that o-ring on later E30s?

                              Thanks, Cory
                              1992 325i Cabrio
                              1988 320i Touring
                              2000 M5
                              1977 530i
                              2015 328i - Euro Delivery/Performance Center Delivery
                              BMWCCA
                              E30CCA

                              Comment

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