2006 Jetta TDI (BRM) with severe power loss

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

  1. Nathaniel Mikkola

    Nathaniel Mikkola New Member

    Jul 10, 2017
    2006 Jetta TDI BRM
    North Carolina
    Hey guys! I'm new here and don't know a whole lot about car repair. I read the articles on limp mode and general power loss on TDI's and the common causes, but I'm a little over my head.

    I've already brought it to a mechanic, and he tried replacing a turbo valve (?) and the fuel filter, which seemed to help some but not completely. He said the fuel filter was really bad, so he recommended I put some additive into my fuel to clean it out which I have done.

    Whereas I'm used to feeling a surge of power when I get to about 1700 RPM, presumable when the turbo hits, now I'm only getting real power starting at about 2500 RPM and even then it's a bit weaker. I also don't hear any turbo whistle like I normally do. The engine light is not on, and IIRC the mechanic said it hadn't thrown any codes. I have a good bit of black smoke coming out the back when driving, especially up hills.

    Any help would be extremely appreciated.
  2. mattredmond

    mattredmond New Member

    Jul 19, 2011
    2006 Jetta TDI
    Dallas, Texas
    You didn't say what kind of mileage you have on it AND I'm no expert. But I'll take a general stab at it and suggest that black smoke means you're running rich. Check for boost leaks. It could also be a failed turbo vane actuator (which is not a replaceable part unless something has changed). I believe a failing camshaft would also cause black smoke but you'd probably have other symptoms before that. I'd check that vane actuator first. If you can get a hand-held vacuum pump, put it on there and see if it holds position when you pull a vacuum.

    By the way, vane actuator (VNT, IIRC) and camshafts are known issues with these cars. I already went through the turbo issue and I'm replacing my camshaft this weekend. This car is a complete pain in the ass. I will never own another VW.
  3. terpsgeorgia

    terpsgeorgia New Member

    Nov 26, 2016
    06 Jetta TDI
    From my very limited experience, you really need something that can read the data stream from the engine management computer to figure this stuff out. If your mechanic does not have access the VCDS or something that can read the data stream, its a bit of a "blind squirrel" scenario. If you read the investigative wikis, most involve some sort of VCDS probing. So far in my 8 months of TDI ownership, my experience has been this is not a "just drive it" car, it requires tinkering, which I personally love to do.

    start at the front and work your way back :) Check your air filter, make sure it is not clogged. Check the air piping at the front and make sure it's not clogged. Make sure the turbo hose at the front passenger side (with the dog collars) is properly connected and seated, as well as the other end near the firewall. check the vane actuator. Verify your vacuum lines are not cracked.

    Matt, I rather enjoyed doing the camshaft a month or so back, I found it therapeutic :)

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