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downpipes are off!!!!

Discussion in 'A4/S4 forum(B5 Chassis)' started by s4 osh, Apr 5, 2009.

  1. s4 osh
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    s4 osh Member

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    right guys on my quest to find what the hell is wrong with my car, the downpipes are now off to do the piggie pipes + i only have one set of 02 sensors :) saves relocating the second ones.... other than the obvious turbos (i wish) is there any prone bits to go wrong on the b5 99 model s4 that i could replace
    and does any one know if the coolant temp sensor would put the car into limp mode if it wos reading wrong codes!!!! because my temp gauge shows that the car is runnin at 65 degrees when driving when i belive that it really should be closer to 90,
    this them comes into coincidence that my car weirldy runs boost when the temp rises to 'normal'
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  2. Blue_Thunder
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    Blue_Thunder Active Member

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    If your car is reading cool it's either a faulty ECT sensor or a knackered thermostat. Pray it's the ECT sensor!
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  3. s4 osh
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    s4 osh Member

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    i take the thermostat is a bitch to get at???? and the ECT is located??????
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  4. s4 osh
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    s4 osh Member

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    oh by the way its all back together now now, and since i have only got one set of lambda sensors i have no cats and no CEL's wooh hoo but still no boost i will order the engine temp sensor and see what that does grrrr!!!! any one want a swap??? hahahah
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  5. Blue_Thunder
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    Blue_Thunder Active Member

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    The thermostat is usually one of the things to do when you're doing a cambelt change.

    The ECT sensor is a black or green sensor (depending on what year your car is) on a black flexi coolant tube underneath the accordian hose. Remove your y-pipe, accordian hose and airbox to get access. The sensors can get really stuck, so try something like WD40 to free it up a bit. Mole grips are your friend at this point!
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  6. Blue_Thunder
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    Blue_Thunder Active Member

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    Did you check your turbo shafts for any play whilst you had your downpipes off?
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  7. s4 osh
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    s4 osh Member

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    no :keule: for some daft reason but with runnin it with a foot and a half of downpipes (noisy as fook) the whistle spooling up sounds beautiful and smooth but there is just no go, soon as i ahve money in the bank i will buy this sensor and let you know how i get on:s4addict:
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  8. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator

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    I doubt the CTS would cause no boost, are there no codes for the N75 etc?
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  9. Blue_Thunder
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    Blue_Thunder Active Member

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    Could be a massive boost leak if you were able to hear the turbos spool up cleanly with ths DP's off (ie: sounds like the turbos are working fine). This will throw the car into limp mode.

    Ideally you want to pressure test it. It may seem like a bit of a trek, but i'd highly recommend going to www.Unit20.org on the Wirral for a proper health check. Grizz will be able to give your car a good going over and will be able to advise on and supply any parts which might need replacing, ie: DV's, TBB, etc.
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  10. stapo69
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    stapo69 All hail the mighty quattro!

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    The thermostat is a long pain in the arse job, trust me!
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  11. andybnwc
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    andybnwc Member

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    i just replaced my temp sensor and it was blue 4 pin square it was like 11.50
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  12. IANS4
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    IANS4 The Fiend!

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    It could be the Y shaped rubber boot where the turbo pipes meet the TB m8, very prone to cracking and easily changed. Mine went a few monts ago, lost all boost it turns out a new one is only about 15 quid from audi.
    Hope you get sorted soon
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  13. s4 osh
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    s4 osh Member

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    right all pipes have been pulled off, checked with a fine eye, put back on with care, and the n75 ha been changed, the maf has been changed and the o2 sensor that showed faulty has been changed,
    but what i am going to do is just order a set of hoses as well as an intercooler and take it from there...... how prone to splitting is the intercoolers????
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  14. Siena
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    Siena Active Member

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    With stock boost pressures, I haven't come across S4 intercoolers split.
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  15. Blue_Thunder
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    Blue_Thunder Active Member

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    There are plastic end caps on the stock intercoolers which can crack.

    Rather than fork out a few hundred on all that stuff, wouldn't you rather just pressure test it first? I bought a pressure tester off eBay for about 40 quid.

    Also worth getting a Vagcom cable to help identify any problems.
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  16. andybnwc
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    andybnwc Member

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    as above a good pressure testing session and vag com
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