Excessive Blowby? (vid)

Discussion in 'Modifications & DIY how-to' started by onemoresti, Aug 9, 2010.

  1. onemoresti

    onemoresti Member

    Excessive Blowby Cause Determined (UPDATE)

    I just started noticing a really strong, stronger than normal exhaust smell while cruising or at idle. I popped the hood and sure enough, smoke is blowing out of the AOS hose that is VTA. This can't be any kind of normal...

    http://www.youtube.com/watch?v=mGD4Pc0l4LQ
     
    Last edited: Aug 29, 2010
  2. integroid

    integroid Supporting Member

    You need to do a compression test. There shouldnt be that much blow by at idle.
     
  3. Mike@TTR

    Mike@TTR Active Member

    Not looking good at all. I take it that it was not like this previously when you were having issues before? Were you running any type of filter on the AOS?
     
  4. Matt@Topspeed

    Matt@Topspeed Member

    Bring it by the shop ASAP Ill have one of the guys Compression check it....thats not good to say the least.

    Matt
     
  5. onemoresti

    onemoresti Member

    No, never had this issue before. The compression and leak down numbers were acceptable, but not great last time approx. 6mths ago. I'll do the CT today, but like you said, not looking good...

    It's strange though. It ran fine Saturday morning on the way to work and I even took it to get lunch, no problems. I changed the oil and pressure washed the motor. I started driving home and it was down on power, sounded weird, and was running rich. I pulled over, and it was misfiring badly.

    I limped it home, and found that it was not firing on #2. Swapped the coil's and it followed to #4. So I installed a used coil pack and all seemed normal.

    Aside from the smoke, the car runs fine...
     
    Last edited: Aug 10, 2010
  6. onemoresti

    onemoresti Member

    This just in....compression test results::wtc:
    #1= 140
    #2= 90
    #3= 140
    #4= 140
    Same cylinder the coil pack went out on.
     
  7. Matt@Topspeed

    Matt@Topspeed Member

    Think of it as an oportunity to build a better STI.

    Let us know if you need anything, I have all the parts in stock to build you a TopSpeed SS1 Short Block.

    Matt
     
  8. Cool_____

    Cool_____ Banned

    You pressure washed the engine and likely that water killed the coil pack. Non firing coils washed out the cylinder likely and killed the rings there.

    That'll be my guess.
     
  9. Mike@TTR

    Mike@TTR Active Member

    Man sorry to hear about that. But as Matt said, time to get that engine you always wanted :) At least that is how it was when my engine finally went.
     
  10. onemoresti

    onemoresti Member

    Yeah, I was hoping it would last to 100K. That was the plan anyway. Gotta break the news to mama and see what kind of funds we have, then weigh the options. What's the best way to convince the wife that I "need" a stroked 35r STi:rofl:.

    Curious though, why did it not throw a CEL? I know on some cars when the PCM detects a misfire, it'll cut the injector to that cylinder. Is that not the case on a Subaru? Not that it matters now anyway. Is it possible that ECUTek has been set to not code for misfires? The same way it doesn't code for cat's or TGV actuators?
     
  11. Kokopelli

    Kokopelli Active Member

    Was the original bad coil pack on #2 or #4?

    I'm not sure if Ecutek can set the misfire threshold and/or turn off the cel but the open source stuff can.
     
  12. onemoresti

    onemoresti Member

    It was the #2 coil. I said that wrong earlier.
     
  13. Mike@TTR

    Mike@TTR Active Member

    Depends on what codes are turned off in the software. I would think it would throw a code, but that is not always the case. If the cylinder was just getting excess blowby it might not even have noticed.
     
  14. onemoresti

    onemoresti Member

    So I was finally able to get a close look at my old block. There were a few very small vertical lines on the cylinder wall in #2, and then....[​IMG]
    [​IMG]
    I suspect the piston had been broken to some degree for a quite while. I couldn't believe how smooth it still ran like this though.
     
  15. motomark

    motomark Loudest fuel pump Tucker Supporting Member

    #4 & #2 both had broken ringlands in my car and my car idled well and still made decent power. I never would have believed it either. It was not until I did a routine oil check and found it magically 1.5 quarts down that I knew something had gone horrifically wrong.

    I wonder how many Stage 2 stock pistoned cars are driving around with cracked ringlands and do not even know it.
     

Share This Page