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S3-8P, TTE420 Stage 3 - Possible Over boosting into Limp Mode Issue.

S3 W Jun 21, 2019

  1. S3 W

    S3 W Registered User

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    Hi all, currently experiencing some issues with an 8P stage 3 S3 running the TTE420 setup & wanted to see if anyone else had similar symptoms regardless of your setup & what actions were taken to rectify the problem.

    Briefly, car runs superb & boosts well that is until you take it to the motorway & push it, first 5-10 minutes on the motorway holding the gears (S Tronic) no issues, shortly after you put your foot down & it will go into limp mode, no engine light comes on, the car still revs throughout the entire range but with no power even at 5k-7k rpm, can still somewhat hear the turbo building boost. If I stop & switch off the engine then back on, all goes back to normal as if nothing happened, boosts nicely till I hold it through the gears & back into no power mode.

    Look forward to any comments regarding similar experiences with petrol turbocharged engines only & actions taken.
     
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  3. S3 W

    S3 W Registered User

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    Further info:

    Had it scanned & the only code that comes up points out overboosting which I believe was the P0234. Have got an appointment booked with the company that mapped the car to replicate & diagnose the problem but at £102.00 per hour, thought id seek some free opinions here first!

    Actions taken so far:

    1) Live boost reading taken a look at, told it was doing 1.8 bar down to 1.6 bar. No signs of overboosting.
    2) Checked connections, all seem to be fine.
    3) MAF sensor, map sensor & N75 seem to be giving normal readings & DV replaced. No indication of faulty parts.
     
  4. abmat

    abmat Active Member VCDS Map User

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    You’re over boosting so there is a fault somewhere. Either boost leaking out causing the turbo to boost more to meet a parameter or turbo boosting over a given parameter so the ecu is knocking it back.

    16618/P0234/000564

    Contents
    [hide]
    16618/P0234/000564 - Boost Pressure Regulation: Limit Exceeded (Overboost Condition)
    Possible Symptoms
    • Malfunction Indicator Light (MIL) ON
    • Boost Pressure too high
    • Reduced Power Output
    Possible Causes
    • Hoses incorrectly connected, disconnected, blocked or leaking
    • Boost Pressure Control Valve (N75) faulty
    • Boost Pressure Sensor (G31) faulty
    • Turbo Charger stuck/faulty
    Possible Solutions
    • Check Charge Pressure Control System
      • Perform Output Test (to check the Turbo Charger)
      • Perform Basic Setting (to check the Charge Pressure Control)
      • Perform Pressure Test to locate Leaks
    • Check/Replace Boost Pressure Control Valve (N75)
    • Check/Replace Boost Pressure Sensor (G31)
    • Check/Replace Turbo Charger
     
  5. S3 W

    S3 W Registered User

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    Hi thanks for the comment, will have a look through.

    Did forget to mention that I've very recently changed the air intake for one that allows more air flow, been told that due to this change, the car will attempt to match the extra airflow with an additional boost which may be being read as overboosting hence the limp mode? either way, the car is booked in for a map tweak to adjust for the new intake so if this is causing the problem it should be gone once map is correctly tweaked for the new intake & will confirm.

    Anyone with a closed/direct air intake induction - recommend checking air filter within as mine had a big hole & wasn't aware until opened to check hence why I replaced the entire system.
     
  6. abmat

    abmat Active Member VCDS Map User

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    Could be. The code should be date stamped when it first occurred. This date may coincide with the new filter.
     
  7. prt57

    prt57 Registered User

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    This is where the fault may be occurring. Sometimes people have trouble if they fit a free flowing intake like a Revo to a stock tune engine. However, a remap sorts it out. So a tweak to your remap should help.
     
  8. samuelh_888

    samuelh_888 Registered User

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    What did you change the intake from and to, and why? I’d have thought if the car was running a TTE420 it would already be well setup.

    The car should adjust for the extra airflow (within reason). Maybe you’ve starved the vehicle of airflow?

    Did you do the upgrade or purchase car like this? Recently? Do you know who did all the work?
     
  9. stbuk

    stbuk Member Silver Supporter

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    As above, TTE420 set up should be well setup and already upgraded. What is the map? Wheres the BAR reading taken from? What intake etc?
     
  10. S3 W

    S3 W Registered User

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    Hi mate, MRC done all the software related work, physical work done by Turner Race Developements, the old filter was completely destroyed so was advised to change intake for an open filter to push over 400bhp, was told to return for a map tweak once the new filter system was fitted but ran into other issues when I returned for the map tweak.
     
    Last edited: Jun 26, 2019
  11. S3 W

    S3 W Registered User

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    Readings taken for boost as was told by MRC, said there's no issue at all with boosting but suspect that may be other factors causing the limp mode. The map is a custom stage 3 map. Intake changed from VWR closed/direct intake to RAMAIR oversized open style intake.
     
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  13. S3 W

    S3 W Registered User

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    To update everyone, found out that the RS4 injectors installed in the car are maxing out at 360 ps despite only serving 15k miles, looking into a new set of RS4 injectors as I believe the limp mode issue may be fuel lacking related.
     
  14. stbuk

    stbuk Member Silver Supporter

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    Have a look at AKS RS3 8V kit, it slots straight in and its what Im running at 400.
     
  15. S3 W

    S3 W Registered User

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    Looks like a great kit, will see if I can find anyone running the new revision RS4 ones part no 079 906 036 N as I can get them for almost half the cost otherwise likely to swap to the RS3 ones. Thanks weren't aware that was an option :)
     
  16. S3 W

    S3 W Registered User

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    Just an update for anyone who reads the thread in the future - after coming past a few old threads, I picked up a trend between faulty injector(s) and over boosting code which was reported by several S3 owners, so if you get an over boosting condition code, even though it makes no sense, check your injectors on a rolling road before investing in a new turbo, I will be upgrading to the RS3 injectors as suggested by others & report if the issue is gone once new injectors have been fitted & mapped.
     
    Forecast.bucket.s likes this.
  17. prt57

    prt57 Registered User

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    Maybe you know already but there is the AKS RS3 injector location modification for the cylinder head that allows the RS3 injectors to sit at approx 90 degrees clockwise to the original position of your injectors in your S3. This then matches the location as if the injector is in an RS3. This improves the injector spray pattern compared to it being in the S3 location. It is quite a quick job for them to drill the new locating holes once the inlet manifold is off as they have a special jig to do the job.
     
  18. B5YNV

    B5YNV Registered User

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    Second the rs3 injectors & head mod I have the same set up on mine running the tte420

    Sent from my SM-G960F using Tapatalk
     
  19. Forecast.bucket.s

    Forecast.bucket.s Registered User

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    Let us know the outcome ;)
     

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