Close

Results 1 to 8 of 8
  1. #1
    Join Date
    Jul 2012
    Location
    Boise Idaho
    Posts
    52
    Rep Points
    62.2
    Mentioned
    0 Post(s)
    Rep Power
    0


    Yes Reputation No

    lost boost after valve cleaning...

    So in a nutshell... Was boosting 17.5psi midrange falling to 14.2ish at redline. Went to dealer to get valves cleaned and left and with same tune now 17.5 midrange 12.49 at redline??? and it's consistant. My boost req and boost actual is like 3psi off now where is was good before. Did a boost leak test on just the mani and cold pressure pipe and all is good? Could cleaning the valves had made car not hold boost as well?? Cant figure it out. Wastegate after PID 5k rpm and up is 57% so wastegates are closed.. Any thoughts guys??
    7 335i 6mt cobbAP+fbo+e85 12.9@112mph so far
    06 c6 vette- sold [email protected]
    06 evo9- sold 11.5@123
    10 genesis-sold slow
    04 srt-4-sold 11.6@126mph

  2. #2
    Join Date
    Oct 2011
    Posts
    1,062
    Rep Points
    1,150.0
    Mentioned
    39 Post(s)
    Rep Power
    12


    Yes Reputation No
    I'd recheck the torque specs for the intake manifold to the head. Also ensure that they replaced the gaskets. A deteriorated gasket can easily cause a boost leak at WOT.

    Log WGDC and see if it has increased significantly.

  3. #3
    Join Date
    Jul 2012
    Location
    Boise Idaho
    Posts
    52
    Rep Points
    62.2
    Mentioned
    0 Post(s)
    Rep Power
    0



    Yes Reputation No
    Boost leak checked the mani no leaks. Maybe some of the walnut shell ruined turbine?
    7 335i 6mt cobbAP+fbo+e85 12.9@112mph so far
    06 c6 vette- sold [email protected]
    06 evo9- sold 11.5@123
    10 genesis-sold slow
    04 srt-4-sold 11.6@126mph

  4. #4
    Join Date
    Mar 2010
    Location
    South Africa
    Posts
    1,366
    Rep Points
    2,072.0
    Mentioned
    42 Post(s)
    Rep Power
    21


    Yes Reputation No
    Click here to enlarge Originally Posted by sharptech Click here to enlarge
    Boost leak checked the mani no leaks. Maybe some of the walnut shell ruined turbine?
    If the did the process properly it's shouldn't go through to the combustion chamber. Remember that boost is a measurement of resistance so a drop in boost does not mean a drop of air flow. Dyno the car and see what the power is like.
    2014 Golf 7 R
    2014 Golf 7 GTI
    2018 Audi RS3 8V
    2018 Porsche Cayenne Turbo

  5. #5
    Join Date
    Nov 2009
    Location
    Simi Valley, CA
    Posts
    9,208
    Rep Points
    12,257.1
    Mentioned
    754 Post(s)
    Rep Power
    123


    Yes Reputation No
    Actual boost numbers are rather irrelevant. What matters is boost vs. boost set point. If it's below set point, you have a hardware or tuning issue. If the set point is below your expectations, you have a tuning issue.
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, N63s, S55s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

  6. #6
    Join Date
    Nov 2010
    Posts
    937
    Rep Points
    562.7
    Mentioned
    52 Post(s)
    Rep Power
    6


    Yes Reputation No
    Check before and after wgdc, 57 after pid seems very high. What's wgdc bank? Theoretically boost could drop due to flow, as George said... Were you also maxing dc before the cleaning?

  7. #7
    Join Date
    Aug 2010
    Location
    Strong Island
    Posts
    3,432
    Rep Points
    3,063.0
    Mentioned
    101 Post(s)
    Rep Power
    31


    Yes Reputation No
    Click here to enlarge Originally Posted by Tzu Click here to enlarge
    I'd recheck the torque specs for the intake manifold to the head. Also ensure that they replaced the gaskets. A deteriorated gasket can easily cause a boost leak at WOT.

    Log WGDC and see if it has increased significantly.
    An intake gasket leak will cause a rough idle as it is a vacuum leak....plus BMW makes them pretty tough, havent seen one fail yet....

  8. #8
    Join Date
    Jun 2011
    Posts
    899
    Rep Points
    1,535.8
    Mentioned
    16 Post(s)
    Rep Power
    16


    1 out of 1 members liked this post. Yes Reputation No
    Similar thing happened when I had the dealer clean my valves as well. I fixed it by removing the diverter valves from all four ports and cleaning a bunch of dirt and walnut shells that weren't allowing them to seal properly. Also when diagnosing the problem I found the vacuum line that runs behind the oil filter housing had broke and someone used a larger piece of tubing as a coupler instead of replacing the whole line. Once I cleaned the DV's my boost was back to normal, and I had the dealer fix the vacuum line. I was throwing codes though and the car would barley hit 8psi, but after cleaning the dv's I was back to 18psi. Hope that helps!

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •