Announcement

Collapse
No announcement yet.

M42 is on its last leg?

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    M42 is on its last leg?

    -m42 blows smoke on startup and until it reaches operating temp for about 15 min. Been thinking since its not thick white smoke and has no signs of milky oil that its not the head. Maybe a seal? 1-10 how hard is it to replace seals? There is also water right above the exhaust in the trunk and i havnt figured a good way to get it out.. maybe the water is dripping in/on the exhaust.

    -It is idling at about 400 rpm. I took the icv off and cleaned it out with carb cleaner and noticed no difference in the idle.

    -Have seen some bits of oil in the spark plug holes, but when i rechecked this morning there was none... weird?

    -When i accelerate with some spirit after about 4/5k rpm i feel like i lose all my power and when i shift its like the clutch has no resistance, but feels fine otherwise.

    -Last of all around 40-50 mph i hear a whining sound.. The diff? Its a vert so it is really hard to figure out sounds since its already so windy in the car. I don't have the jack stands to lift the rear and let the back wheels spin like i've seen suggested on other threads.

    Sorry i know its alot. I drive this car everyday for about 30 min in each direction to work. I am just trying to get it all sorted out so that i can trust it.

    Thanks R3V
    Tags: None
    #2
    I would start with a compression test to verify you have a sound engine. If that pans out, start looking for cracked hoses. Google "mess under the intake" It's on here or at the M42 club site, probably both.

    Good luck.

    Comment

      #3
      The motor was "rebuilt" from what the PO told me. I haven't gotten any receipts from the owner, but i'm still trying. The extra hoses from under the intake have already been deleted during the "rebuild" I will be getting a compression test very soon and have my eyes on a verified rebuilt head.

      Comment

        #4
        step 1: ignore everything the previous owner said.

        If it comes to it I suggest rebuilding your own head yourself. ie taking yours off and taking it to a machine shop. Buying second hand parts that are "Verified" is a recipe for disaster. its going to cost you lots of time and money to swap the head regardless of what one you get so at least be damn sure that the head you put back on is in perfect condition. not told it is in perfect condition by a second hand seller.

        What you suggest sounds like maybe valve stem seals causing your issue with burning oil, which you will get done when you do the head.

        A wet and dry compression test and a coolant system pressure test will give you an overall feeling for the condition of the engine.

        Your differential probably needs a rebuild too. Whining is probably pinion bearing. Remove diff and drop it off at a diff shop. Pay the man to put it in working order and you will never have an issue with that diff again.
        Last edited by e30davie; 02-23-2018, 01:31 PM.

        Comment

          #5
          going to get the test done on Sunday. Was fiddling around in the motor bay and noticed 3 of the valve cover bolts are stripped/the holes on 2 are stripped out... so tomorrow i'm going to learn how to tap a hole.. any tips before i dive into this? I've seen my father do it before and tbh it seems pretty straight forward. The only issue i am worried about is that i don't have a vacuum or to suck the shavings out.. I have seen some post about using grease and then a cotton swab to get them out... opinions?? I'm hoping this will fix the low idle and oil in my spark plugs. Gonna get new valve cover gaskets as well.

          Comment

            #6
            Find a cheap shop vac on Craigslist or see if your local Harbor Freight has any offerings. Sears has (had?) 50% off tools too. Time to stock up.

            In another post you said you had a tablespoon of oil in every spark plug. You likely have bad valve stem seals which means that the engine wasnt rebuilt or wasnt rebuilt well.

            Fortunately valve stem seals arent hard. You need a tool to pull the seals though, otherwise you risk mucking up the engine with pliers. Its very easy to reach too deep and scuff the valve guides.


            If worse comes to worse, I have an M42 long block in Houston. I have pretty much a duplicate or triplicate of every M42 part (minus hoses of course). I also just did the mess under the intake (MUTI) and could give you feedback.

            Good luck.

            Comment

              #7
              ^
              Oil in the plug wells is 100% a sign of a plug well gasket issue, probably not stem seals.

              OP, you probably already figured this, but shavings really are best dealt with using a vac, grease just keeps them in place. Also, a helicoil or threaded insert are probably better bets than tapping an aluminium component for the sake of longevity and reusing stock bolts.

              Comment

                #8
                m6x1.00? Ive never tapped a thread, but from what i've read it seems rather simple. I have the bolts out, so would the helicoil just be an insert? compared to just getting the tap kit and re threading the hole by hand?

                Comment

                  #9
                  Yes, M6X1 is what you want, the whole process is simple, take your time and it will be fine. Yes, it's an insert, you clean out the hole with the prescribed drill bit, then tap a slightly larger size for the helicoil to thread into.

                  This link has everything you need to know about repairing the valve cover bolts and is the guide I used when I had to fix mine.
                  http://bmw.e30tuner.com/articles_vchc.php

                  Comment

                  Previous template Next
                  Working...
                  X