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    Help Diagnosis needed-Video

    Please view this youtube video:
    E30 Engine starts fine cold. idles at 800 rpm. then within a minute, begins to smoke, and the engine gets progressively rougher. view video to see how quic...


    tell me what you think the problem is.

    Background:
    About a month ago I installed a starter. The engine ran okay, but a little rough. the coolant light stayed on al the time but the gauge read mid-range (normal). I topped up the coolant resivior several times thinking i had air pockets in the system, and it was just working the air through the system. about two weeks ago I seemed to get the coolant leven correct, becasue the light stayed off, and the gauge read normal. but around that time I noticed the idle would surge up to about 1500 rpm. and if i had the AC button on, the car would rev to about 2000 rpm. turning off the AC usually allowed the car to go back to 800 rpm. but occationally, the idle would surge even when the AC was off. the other day i tried to get to the bottom of this so I had the car started and idling, and i started to press on the vaccum hoses jiggling them around listening for any changes. sure enough, when i reached under the throlle body and pressed on the hose under there, i could hear a hiss of leaking air and this corrosponded to a change in RPM. it seemed like there was a loose hose under the throttle body, and if i poked it just right, so that it was not leaking, the idle seemed perfect. so, i figured I better take off the hoses leading to the trhrttle body, and see if i could get in there to see exactly what was loose. i took off the large intake boot, checked all the electrical connections, as well as the hoses and the book itself for cracks, etc. I didnt see anything that was too obvious, so I put it all back together, and replaced a couple of suspect looking hose clamps. When i went to sytart the car the starter turned about 1 revolution of the flywheel and stopped cold, like i'd left a wrench in the engine bay. I checked. saw nothing and tried again. same thing. one turn, then an abrupt halt. scarry and unnatural. i looked in the engine again and then i saw that I'd failed to reconnect the electrical connecter to the air flow meter. I reconnected this and the car started, but that is when i noticed the strange white smoke. the smoke does not look like blue oil smoke, ive had enough british cars to know what that looks like, but ive never had a blown gasket so i dont know if this is the dreaded white smoke. How could I have blown a head gasket, or cracked the head? the car wasn't running? it never overheated, although the last time I had it out, I do remember the temp guage in the dash was bounching all around, it looked like a bad sensor, or a loose electrical connection, becasue it was bouncing from full cold to mid-temp and back, snapping back and forth. Ive had the sensor for the guage go bad twice in a year, so i thought it had gone bad again. but even with this erratic behavior of the guage, the highest it ever read was mid-level, at the most, a touch above mid-level, but no hotter. so what gives?

    the video probably teels you more than this whole backstory, but i'm worried about a cracked head.

    help is appreciated.

    #2
    E30 Engine starts fine cold. idles at 800 rpm. then within a minute, begins to smoke, and the engine gets progressively rougher. view video to see how quic...

    Comment


      #3
      The smoke looks to me like vaporized coolant. And that would be from a head gasket failure or a cracked head. The surging idle is probably from intake leaks. The rough idle is probably a combination of intake leaks and coolant fouling the plugs.

      Pull the head, have it checked for cracks, surfaced, valves ground, new seals, etc. Replace every hose, gasket, and seal associated with the intake as well as the dip-stick o-rings and oil filler cap. While the head is off, replace all cooling system hoses, water pump, thermostat, radiator, fan clutch, expansion tank & cap. Use new plugs when you put the head back on. The odds are that the engine also needs a new O2 sensor, distributor rotor & cap, and ignition wires. During the down time while the head is at the shop. have the injectors professionally cleaned, rebuilt, and flow tested.
      The car makes it possible, but the driver makes it happen.
      Jim Levie, Huntsville, AL

      Comment


        #4
        You were probably low on coolant because it was burning it. It has apparently gotten worse. Probably a bad head gasket. You can do checks to confirm a blown gasket or cracked head. If it is blown, you should have the head checked by a machine shop for cracks before reassembly.

        Comment


          #5
          thanks Guys!

          to jLevie; would vaporized coolant build in volume like it appears to do in my video? If you watch the time you will see that in less than three minutes of running from a cold start the smoke is pouring out the tail pipe How could the water in the cooling jacket boil that quickly and that vigorously? I could accept the theory that the surging idle is due to intake leaks and if a ton of water is getting into the combustion chamber, then i could see it messing up the mixture to the point where it is misfiring. this makes me think that the leak is huge, not some little seepage.

          Urbancynic: thanks, yes, it might seem as though the low coolant light staying on may have been caused by the car "eating" coolant via a leak, but I don't think so. I really think that I never quite filled the coolant correctly after I had to bleed off about 1/2 of the coolant when i changed the starter motor. the coolant light stayed on from the minute i finished the starter job. In my opinion it is more likely that there were air pockets in the system, and that it kept accepting a "top up " of water becaue i didnt get the car up to full operating temp for few rides. there were about 2 weeks of driving where i got the coolant light to stay off, and the temp gauge read perfect during this time. this period of correct running included two round trips of over 150 miles each, of highway driving, and some steady driving at 80mph for sustained periods. so i dont think it was buring coolant then. if it is burning coolant now (and it looks that way) i believe that is something new.
          what are the checks I can do to confirm a head gasket failure? ive looked at the oil on the end of the dipstick and it looks normal, not milky or frothy. Ive looked at the coolant and it is hard to tell if there is any contamination, becasue I'm not 100% confident that the coolant looked pure before the problems started.

          1. Does anyone know if the chemical testing kits that test for the presence of exhaust fumes in the coolant will work on the e30? the test demo i saw looked like it utilized a radiator cap on top of the actual radiator.
          2. I do my own work. do we have any estimates on the time required to tear down the motor to the head gasket?
          3. any special tools required?

          4. I really dont want to spend much money on this car right now. are all head gaskets created equal? where is the best place to source this part?
          5. how much should i expect to pay to ahve the head checked by a machine shop?

          Comment


            #6
            As the engine heats up a leak between the cooling system and a cylinder can get worse (or better as the case may be). In this case it looks like it gets worse and more coolant is entering a cylinder(s). The coolant isn't boiling, it is being vaporized by combustion in the cylinders. A surprisingly small amount of coolant makes a lot of white smoke.

            How much the head work will cost depends in part on how bad the damage is and how much of the work you do yourself. If you take the head to a shop disassembled and all that is needed is surfacing and valves ground the cost may be on the order of $500. It would be quite a bit more if the shop has to disassemble and reassemble the head.

            If you do tear the head down, you have to use a driver on the rocker arm shafts that only bears on the shaft itself. If you don't you'll damage the plugs in the shafts and have to get new shafts. The only other special tool is a valve spring compressor. Oh yeah, loosen the cam shaft nut before removing the timing belt.
            The car makes it possible, but the driver makes it happen.
            Jim Levie, Huntsville, AL

            Comment


              #7
              I have a vallve spring compressor. not sure if it will work on a BMW head. it is designed for motorcycle heads, so it may be too small.

              what a PITA.

              Comment


                #8
                Sears, and other places have a C-arm type compressor that will work.
                The car makes it possible, but the driver makes it happen.
                Jim Levie, Huntsville, AL

                Comment


                  #9
                  I ame getting the head into the machine shop tomorrow. I removed the head today and did not see any cracks. I used a magnifying glass but still coildnnt detect anything. Where should I be looking for possible head cracks?

                  Comment

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