Announcement

Collapse
No announcement yet.

Hydro-lock question??

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

    Hydro-lock question??

    I am working on a m20b25 engine that has hydo-locked bending #1 rod, causing the piston to come apart.

    What happened-
    car was having injector harness issue (common e30 problem). harness was corroding under the TB, due to the TB leaking coolant on to it. the connector was cleaned and die electic grease was put in the connector. this seemed to fix the problem most of the time. when the car started sputtering it would be shut off and playing with that plug would make the sputtering go away. the last time it happened, the car was started up and there was an instantly a knock. this is when the rod benty and things went down hill from there.

    when the engine came aprt it was obvious it had hydo-locked. my question is: has anyone ever seen (in an e30) hydro-lock caused by an injector harness shorting out? I have ruled out water getting in the engine because it was not raining and the car had not been drivin through a puddle, or anything like that.

    thanks for any help i can get.:D
    Tags: None
    #2
    There is a TSB from BMW about leaking injectors causing hydro-lock.

    Comment

      #3
      holy crap, i've honestly never heard of that before
      1989 cirrisblau-metallic 325i

      Comment

        #4
        Yes that can happen. The TSB (Technical Service Bulletin) was aimed more at the latter engines but a load of liquid in the cylinder be it water, coolant or fuel will blow the works.
        I'm Not Right in the Head | Random Rants and other Nonsense1st Order Logic Failure: Association fallacy, this type of fallacy can be expressed as (∃x ∈ S : φ(x)) → (∀x ∈ S : φ(x)), meaning "if there exists any x in the set S so that a property φ is true for x, then for all x in S the property φ must be true".

        Comment

          #5
          my next step is to check the resistance in the injectors. it would be crappy if they caused this because they are the 19#s and only have about 1500 miles on them.

          what i am still wondering is if the bad conection in the harness could cause one of the injectors to open up? I have actualy seen this happen on the older digifant volkswagens. they had an issue of shorting themself out. the injectors would still be good.

          its making my head spin thinking about it. i dont want to put the new engine back in and have it happen again. haha

          Comment

            #6
            I have seen this on a Jeep, blew the whole engine to smitherines. All it takes is the injector to be stuck open or powered up all the time. I could imagine the harness problems causing this by sending ground or power (whichever opens it) to the injector all the time. This would explain your driveability problem you had before your engine went kaput. The cylinder will fill with gasoline and the next time you start the vehicle it's game over.

            MAKE SURE YOU FIX THE HARNESS! Re-wire everything if you have to. The to be sure it's fixed, power up the car with the fuel rail plugged in and make sure no fuel comes spilling out. Remember, you will get a "priming pulse" of one squirt when you first turn the key to the run position.


            Turbo M20, MSnS, 38lb, 3" no cat, RPI 12.2", ATS DTC, 240whp/240wtq, Lmnop. www.DonsGarage.net

            Comment

              #7
              Originally posted by mfing fbm View Post
              my next step is to check the resistance in the injectors. it would be crappy if they caused this because they are the 19#s and only have about 1500 miles on them.

              what i am still wondering is if the bad conection in the harness could cause one of the injectors to open up? I have actualy seen this happen on the older digifant volkswagens. they had an issue of shorting themself out. the injectors would still be good.

              its making my head spin thinking about it. i dont want to put the new engine back in and have it happen again. haha
              I'd say that it would take more than corrosion in the C191 connector to cause an injector to hydro lock the engine. And even if that happened, it would affect at least three cylinders.

              I think a more likely cause would be a leaking injector or head gasket failure. With the odds favoring a head gasket problem.
              The car makes it possible, but the driver makes it happen.
              Jim Levie, Huntsville, AL

              Comment

                #8
                Originally posted by jlevie View Post
                I think a more likely cause would be a leaking injector or head gasket failure. With the odds favoring a head gasket problem.
                that's what I was thinking... an injector couldn't deliver that much fuel, that fast, on a running engine
                1989 cirrisblau-metallic 325i

                Comment

                  #9
                  I think the same about head gasket as well. However, I did have a technition working on a problem TBI 454 Chevy Suburban who couldn't solve the runability issue and was dumping an injector at full for so long it washed the cylinders of oil and overheated and seized up all the oil rings and we had to replace the engine.

                  Comment

                  Previous template Next
                  Working...
                  X