Boost levels on BRM, actual versus expected observations - is this normal.

Discussion in 'Mk5 VW Jetta, Sportwagen, and Audi A3 TDI forum' started by terpsgeorgia, Jul 11, 2017.

  1. terpsgeorgia

    terpsgeorgia Member

    Joined:
    Nov 26, 2016
    Messages:
    42
    Car:
    06 Jetta TDI
    Location:
    Cleveland, Georgia
    I am new to TDIs and diesels in general. But have many years of messing around with cars....

    So my TDI seems to be a bit sluggish lately (after the recent cam replacement about 1,000 miles ago). In poking around, I noticed the vacuum hose to the VNT was cracked and replaced that. I also noticed there seemed to be a fair amount of crude in the intake system - not sure it is greater than the 10mm limit but, is there a wiki for the BRM for removal of the intake?

    In tracking the Torsion Value and boost pressure measured versus target, just wanted to see if my observations are "normal behavior".

    Basically, when the boost is in the 1000 area, my measured versus target is pretty close if not dead on. But when the car is under load (uphill for example) and the rpms spin up a bit, boost is about 75% of target - example 1500 when the target is 1900, 1200 when target is 1500. I also noticed the torsion value in such situations drops from 0.98 to 0.49.

    So my question is, is this normal? Perhaps I have a boost leak or restriction? I ask because I have seen systems where lagging below the "target" is not catastrophic, to a degree. I just don't know where those boundaries are here.
     
    Last edited: Jul 11, 2017
  2. terpsgeorgia

    terpsgeorgia Member

    Joined:
    Nov 26, 2016
    Messages:
    42
    Car:
    06 Jetta TDI
    Location:
    Cleveland, Georgia
    Ah, so I went into the wikis via a different path and found this:
    http://www.myturbodiesel.com/wiki/turbo-stop-screw-adjustment-tdi-engine-zip-tie-engine-hesitation/

    So the dealer I bought the car from claimed he was a diesel expert from Czech Republic. When he said I should just use full synthetic 15w40 Diesel oil with zinc additives, I kinda decided to take his suggestions with a grain of salt. Maybe I underestimated him.

    When I was doing the cam shaft replacement, i removed some of the vacuum lines to get them out of the way, including the actuator. I noticed a wire wrapped aroudn the actuator vacuum line that went below an figured it was there to hold the vacuum line. Did not think much of it, reattached the hose on reassembly and went about my business. Lo and behold, I am guessing that was his zip tie implementation. Last night, I hung it over the vacuum hose rather than just over the connector and performance seems improved. Actual pressure tracking more closely and car seems less sluggish. Still need to play around with it but thanks again for the awesome wikis!
     

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