Volvo 740 Turbo with "shaved" housing with a hole in it ?

Discussion in 'Volvo 740' started by circuit slave, Feb 18, 2006.

  1. Hi everyone I started another thread in which I lost turbo pressure.
    Well, it turns out that the 2" aluminum foil-type hose which goes from
    under the airbox to the back down by the exhaust I assume was very old
    and had holes. I replaced it and have boost but the problem I noticed
    is the Turbo housing was shaved with some type of tool and a hole was
    made?

    To relieve pressure? Why would they have done that? I mean maybe
    that's why I dont' have full boost turbo power and maybe why the guage
    is somewhere around 10 o'clock when I'm not even moving?

    I was going to plug it with JB Weld, but now I'm afraid. I mean I
    don't want to blow up the thing. Do you think the previous owner had a
    pressure problem so they did the mickey mouse job and relieved the
    pressure by shaving the metal housing and alowing a hole for pressure
    relief?


    Any suggestions are appreciated. Thanks !
     
    circuit slave, Feb 18, 2006
    #1
  2. circuit slave

    James Sweet Guest

    Can you get a picture? I can't think of any hole that should be in the
    turbo housing, where exactly is it?
    As I said earlier, the guage is supposed to sit around 10 o'clock when
    the car is not running. Black is vacuum, yellow is boost, the place
    where they meet is atmospheric pressure, if the guage is not pointed
    there when the engine is off then it's broken.

    Did something wear on it and make a hole? Or is it on the exhaust side?
    Perhaps the car ran lean and overheated the exhaust housing, melting a
    hole in it.
     
    James Sweet, Feb 18, 2006
    #2
  3. No, James. The ACTUAL TURBO CHARGER housing was shaved down (grind the
    metal down on one the left side) and a whole was created. I believe
    its a Garrett (it's got a metal little label that's all greasy)

    So maybe that's why I've had the leak all this time? But the hose I
    replaced helped. I mean I accelerate and such.

    Now by "exhaust side you mean after the intercooler and AMM, right?
    Because I mean the ACTUAL TURBOCHARGER housing, if that makes sense.
     
    circuit slave, Feb 19, 2006
    #3
  4. I took some pictures of it. All it looks like is picture the "donut
    housing" of the turbo charger and shaved down one side. It looks
    really weird. I can email you the pics.
     
    circuit slave, Feb 19, 2006
    #4
  5. I think you will find that James may be querying whether your car was fitted
    with EGR (the hole being on the manifold just above the turbo mount, should
    have a metal tube going to the EGR valve) that caused the PO a problem so he
    removed it.

    All the best, Peter.

    700/900/90 Register Keeper,
    Volvo Owners Club (UK).
     
    Peter K L Milnes, Feb 19, 2006
    #5
  6. circuit slave

    James Sweet Guest


    Yikes, that's definitely a problem. By exhaust side, I mean the exhaust
    turbine housing, as opposed to the compressor housing. The former is
    cast iron and will be all rusty, the latter is aluminum and facing the
    front of the car.

    Are your engine mounts completely shot? Only thing I can think of is
    maybe the turbo has been rubbing against something but I've never seen
    that happen.


    You can see a good picture here of a T3
    http://www.servia.fi/~professi/AdvHTML_Upload/files/timon_tiomi_012.jpg


    As well as another showing the inside, with the compressor and turbine
    blade assemblies joined to the shaft running through the center
    cartridge. The wastegate actuator is also visible.

    http://www.lanciadelta.org/images/garrett.jpg
     
    James Sweet, Feb 19, 2006
    #6
  7. circuit slave

    James Sweet Guest


    I've never encountered a Volvo with EGR, I don't believe they used it in
    the US market. None of the manifolds I've ever seen have had any unused
    holes in them. The tube I'm referring to is a corrugated aluminum hose
    which connects a sheath over the exhaust manifold to the airbox, the
    purpose being to draw heated air into the intake when the engine is cold
    to accelerate warmup. There's a wax thermostat in the airbox which
    operates a flap valve to close off this tube, if it gets stuck open and
    hot air is drawn in once the engine has already warmed up then the air
    mass meter can be damaged.
     
    James Sweet, Feb 19, 2006
    #7
  8. Yeah, I've opened the airbox when I changed the air filter. I saw that
    flap that flaps open/closed. I accidentally "touched it" (because the
    car is so old and never maintained, touching can damage :p) and part of
    the flap crumbled. Where is the thermostat in there?


    Looking at that pic---I don't know which side is which, hehe. But Okay,
    well, interested, here are the pics !

    http://i29.photobucket.com/albums/c300/circuitslave/56bfbefc.jpg

    http://i29.photobucket.com/albums/c300/circuitslave/17edccea.jpg

    http://i29.photobucket.com/albums/c300/circuitslave/KIF_0569.jpg
     
    circuit slave, Feb 19, 2006
    #8
  9. I see, well, the whole is on the compressor side, as you can see.
     
    circuit slave, Feb 19, 2006
    #9
  10. circuit slave

    James Sweet Guest


    Crap! That's sure the first time I've ever seen THAT happen! That's a
    Mitsubishi turbo, same one I have in my '87. It's pretty clear that the
    aluminum hose has ground a hole in the compressor housing from years of
    rubbing, it's no wonder you're losing boost and getting funny sounds.
    Try patching it up with some JB Weld, just don't get chunks inside the
    turbo. A better solution, if you're able to do this, is to remove the
    housing and take it to a welding shop and have them TIG the hole closed
    but removing it with the turbo on the car is a real pain, there's not
    much wrench access.
     
    James Sweet, Feb 19, 2006
    #10
  11. James, I think it was intentional--there's no way that could have
    happened with rubbing.

    I'm looking into it---FYI, the Volvo was a single owner--my uncle and
    it's been like that for years. And his son (who let's just say is had a
    somewhat drifty life) told him "Dad, I know a guy who fix turbo
    charger's for like $75."

    It's steel, no way that could have happened, IMHO.
     
    circuit slave, Feb 19, 2006
    #11
  12. circuit slave

    zencraps Guest

    Would JB Weld hold up to the heat generated by a Turbo at full boil?

    I think not.
     
    zencraps, Feb 19, 2006
    #12
  13. The hole was hidden by that aluminium pre heat hose. Looking at the
    car --everything looks fine no obvious signs. I don't know, not to
    jump to conclusions, but it just looks devious.
     
    circuit slave, Feb 19, 2006
    #13
  14. Without pulling the turbo, what else would work? Muffler bandage
    maybe?

    I replaced the pre heat house, as you can see in the pic, but the hole
    was blocked by the old house, that's why it makes me suspicous.
     
    circuit slave, Feb 19, 2006
    #14
  15. circuit slave

    James Sweet Guest


    It's aluminum, and it's definitely a hole rubbed in it, look at how it
    lines up there, I'd bet money that's what happened. I have the exact
    same car with the exact same turbo, there's no hole there and absolutely
    no reason to have one. Aluminum is soft, my alternator has a gouge
    rubbed in it from the plastic cable sheath rubbing on it over the years,
    even steel will wear like that if a bit of oily road grit gets in there,
    it's the same way you can polish scratches out of metal or glass with a
    cotton cloth and some abrasive powder.
     
    James Sweet, Feb 19, 2006
    #15
  16. circuit slave

    James Sweet Guest


    Not on the exhaust side certainly, but on the intake it might, it'd be
    iffy though. Best solution aside from replacing the housing would be to
    weld it.
     
    James Sweet, Feb 19, 2006
    #16
  17. I'm sorry, my bad. Yeah, aluminum. Well, it's on the intake side, so
    couldn't JB weld work?

    I talked to my other uncle who says, well, it's not like it's on the
    exhaust side, so it might work.

    I'd get it welded but--well, It's my daily driver and if it's from
    wear, it's been like that for years, so a month or two isn't going to
    make a difference I think.
     
    circuit slave, Feb 19, 2006
    #17
  18. FYI for clarification the turbo lacked power since about 2002. I
    thought I lost power, but I never really had it to begin with, hehe.
     
    circuit slave, Feb 19, 2006
    #18
  19. circuit slave

    James Sweet Guest


    Well patch it with something, with a boost leak like that you're burning
    a lot of extra fuel since it's metering the air before the leak and
    fueling accordingly. You'll burn up your catalytic converter driving it
    like it is.
     
    James Sweet, Feb 19, 2006
    #19
  20. JB Weld is spec'd for up to 500F. http://jbweld.net/products/jbweld.php I
    doubt the compressor side gets much above 300F and the pressure is
    insignificant.

    The way I'd do it is to clean the surface with brake cleaner and JB Weld a
    piece of metal over it - I'm concerned the JB Weld might crack if you try to
    bridge the void with it. A coin that is slightly larger than the hole will
    conform to the curved surface reasonably well. JB Kwik or a small bead of
    the putty equivalent will hold the plug in place without the need to come up
    with a fancy clamp; you'll just need some patience to hold it until it
    sets - about five minutes. Then mix some JB Weld to apply around and over
    the plug. Epoxies harden best when hot, so the car should be drivable within
    an hour or so if you don't wind it up too much.

    BTW, I would expect noticably better performance and fuel economy from
    repairing the hole. It is having the same effect that any other hole in the
    boosted side of the intake has: it draws more air through the AMM than the
    engine is really using, which convinces the ECU to inject fuel to match. I
    don't know how it got this way, but you'll be a lot happier when it is
    fixed.

    Mike
     
    Michael Pardee, Feb 19, 2006
    #20
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