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help before i go mad lol

Discussion in 'A4/S4 forum(B5 Chassis)' started by evilscotsman, Oct 19, 2010.

  1. evilscotsman
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    evilscotsman Space Cowboy

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    [Oct 19, 2010]
    just out in the car, boost still too high, bonnet catch still broken, put the foot down to get up a hill and got a huge BANG like a shotgun, something ricocheted around the engine bay (sounded like) then drove as normal, still boosting, still pulling ok, but theres coolant pissing out everywhere now when I stopped, what the hell could have blown by excessive boost that could have popped the coolant system? maybe the HG has gone and pressurised the water jacket but surely it would run *****?

    Anyone got a pic of the bonnet catch mech from above so I know where to push / pull, got the grille off but still cant open it now, cant tell what im supposed to be levering on to open it from memory.....and jacking it up was no good, no access to the catch but can feel it when the grille is off.


    aaaaaaaaaaaaaaaaaaaaaaaaargh!
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  3. Jonion
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    Jonion Member

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    [Oct 19, 2010]
    Not neccessarily all that badly.
    Hard to say if you'd notice it (dramatically) immediately if it's been going for a while.
    I had one that was going for ages(weeks) pressurising the cooling system before finally popping a pipe off. It still ran well enough to finish the track day and drive me 200 miles home. And that was with only 150bhp NA.
    Yours being turbo may hide it better.
    If it's pressurising the cooling system and not sucking water into the engine......

    I think your bonnet problem is the key.. wish I knew these cars well enough to offer something worthy.
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  4. evilscotsman
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    evilscotsman Space Cowboy

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    [Oct 19, 2010]
    that sounds likely there mate, the excessive boost before i put a gauge on it, leading to the HG going in a small area, pressurises the water system then one day its too much for the hose, and the closed system would have hidden the HG leak till the hose / radiator popped....doh!

    so thats a TB, HG, oil, filters, etc etc and this was supposed to be my cheap workhorse lol
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  5. Jonion
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    Jonion Member

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    [Oct 19, 2010]
    That I truly empathise with !
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  6. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Oct 20, 2010]
    Why condemn it until you've fixed the hose?

    Full throttle means maximum heat output, so its possible that its just been a weak hose.

    Plenty of tuned TDis around running silly boost with the fuel to match. PCP will be much higher in a tdi running 180hp than in one running 110hp with a bit too much boost.

    That said, if its broken why are you still driving it? You've been posting on here for weeks about the overboosting, you know exactly why its overboosting, but you've not actually fixed it... That i dont empathise with.
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  7. evilscotsman
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    evilscotsman Space Cowboy

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    [Oct 21, 2010]
    erm, it was underboosting for weeks, when I eventually found the boost leak the other week and fixed it, i discovered it was now overboosting yeah, and tried to free the sticking vnt but even now thats moving freely most of the time, it still sticks sometimes. I fitted the boost gauge so I could watch it from getting too high but I took my eye off it for a bit when I had to climb a slope, it must have hit 2 bar and went pop. Since it was my only transport and payday was a long way off I couldnt previously take the chance of removing the turbo and breaking a stud or something and getting stuck so I havent really fixed it, not yet, but it went bang 2 days before I get paid, bad luck there but I am just blogging on here, not looking for sympathy lol.


    all i need help with actually is opening the stoopid bonnet :banghead:
    Last edited: Oct 21, 2010
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  8. evilscotsman
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    evilscotsman Space Cowboy

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    [Oct 21, 2010]
    ok...got it open at last from underneath with a long metal tube just by pushing on the lever.

    anyway, when i pulled the undertray out, it was full of little bits of black plastic.....i thought what the hell are these?

    I looked down into the engine bay and the viscous coupled fan is no longer there! The hub is the only thing left. I put a bit of pressure on the small expansion pipe and the radiator has about 9 holes in it.....the fan had shattered and gone straight thru the alloy core.

    So, head gasket seems perfect, still running sweetly but obviously needs a rad now - better than a head gasket and timing belt :woot:

    The opportunity having arisen, I pulled the intake pipes and the egr off and disconnected the vnt actuator, it is fine but the vanes are sticking at the turbo, so I fed a tube down the egr hole into the turbine and injected mr muscle oven cleaner (sodium hydroxide) and filled the turbo with foam till it came to the top of the sunken hole to the exhaust - it cannot get to the alloy head as it would eat it and make hydrogen gas, but its just below the hole to the turbine and in seconds the vnt lever was free as a bird!

    Its gonna sit in there and then ill blow it out the exhaust when its had overnight to totally work, superb.

    I also discovered the vnt lever can be adjusted by rotating the actuator and just bolting it down again. Same action as adjusting the thumb-wheel (which will be seized solid) so I can turn down the boost. I think the previous owner has adjusted it up, as the intake is clean as a whistle (no carbon just an oily skin) and so I just need to test and set max boost at about 18psi but really im going to tune the actual to requested map once the rad is replaced and everything is back together. (my vag lead is working now too, chinese seller did not realise that 2 drivers are needed. Might have a bash at repairing my genuine one too if i can get a decent soldering iron, as i dont work in manufacturing now lol no gear, it suffered the 12v problem on a golf as it just predates the protection added by ross tech)





    woot woot
    Last edited: Oct 21, 2010
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  9. Jonion
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    Jonion Member

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    [Oct 21, 2010]
    Result.

    Really glad you got it sorted .. well almost.

    A good day for cheapo workhorses today then :cool:
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  10. evilscotsman
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    evilscotsman Space Cowboy

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    [Oct 21, 2010]
    it is! And i got the legacy closer to mot and quieter by removing all the heatshields cos they did your nut in, thereby exposing the 2nd turbo so it can have the gasket done.

    good day all round really :)
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