JMB RetrofitsSky Insurance
Results 1 to 24 of 24
  1. #1
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66

    TDi down on power

    i just got a 1.9 tdi 130 can hear turbo spool at around 1500 rpm to 2300 rpm but the turbo whistle sems to disapear after 2500 rpm to be down on power dont get a surge of power at 2000 RPM any more like it used to since its been down on power the car dose not smoke at all


    thanks
    Last edited by anilkumar; 14th August 2010 at 14:43.

  2. # ADS
    ADS
    Join Date
    Always
    Location
    Global
    Posts
    Many
     
  3. #2
    Chugger

    Status
    Offline
    Join Date
    Nov 2009
    Location
    North Devon
    Posts
    2,716
    possible maf.

    Need to get it vagcommed.

    This forum aint to handy for diesels, might be worth posting on ukmkiv's
    57 A3 2.0 TDI Sportback (140)

  4. #3
    6th Gear

    Status
    Offline
    Join Date
    Aug 2010
    Posts
    1,540
    some of us are quite good with diesels tho........

    sounds like the variable vane system on the turbo not working right.
    functional description;
    vacuum is supplyed from the brake servo pipe down a little vac pipe to an actuator valve. this actuator valve is switched in and out by the ecu on a varying duty cycle according to running conditions. to supply certain amounts of vacuum (down another little vac pipe) to the variable vane actuator on the side of the turbo.
    theres a mechnical set of vanes inside the turbo that can move to direct the exiting exhaust gas into the impeller or away from it.
    this system allows the ecu to vary the turbo speed/supplied boost to the engine. example, allowing the ecu to spool the turbo up at lower revs or drop it off at high revs low throttle......

    common faults are;
    -the turbo vanes sooting up inside the turbo and seizeing up. usually you get over boost fault codes.
    -vacuum leaks from split vac pipes rubbing on things and wearing through.
    -the actuator valve can go faulty. where the valve actuates fine but leaks vacuum back.

    from the description of your fault, id put a tenner on it being the valve. theyre mounted on the baulkhead to wards the n/s. theres two or three of them (the other valves work the egr valve and "stop" flap on the inlet manifold). you'll need to identify which one it is by following the vac pipe from the turbo acuator. the actuator valves are about Ł40 i think?
    Last edited by murran; 14th August 2010 at 17:05.

  5. #4
    6th Gear

    Status
    Offline
    Join Date
    Aug 2010
    Posts
    1,540

  6. #5
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66
    thanks for the info if the turbo vanes were sticking would car going in to limp mode because it dosnt sound like its going in to limp mode
    looks like i will have to get it scanned this valve u mentioned is it the n75 have u got a picture of the actuator valve

  7. #6
    6th Gear

    Status
    Offline
    Join Date
    Aug 2010
    Posts
    1,540
    they look like the one in the ebay link above.

    if the vanes in the turbo are seized, they seize in the boosting position. which is why you get over boost fault codes, as the ecu is trying to back the boost off using the vanes but the boost pressure sensor is seeing overboost.
    when this happens the ecu will limit the fueling so it doesnt start bending conrods. you'll feel a drop off in power, but when you turn it off and back on again this resets. it'll feel fast again, till the second or thrid time you boot it, it'll see the overboost again, and the power will drop off.

    your describing, on accelaration, an initial boost then it weeding off? the same everytime you accelarate?

  8. #7
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66
    yea its the same every time you accelarate turbo come in at around 1500RPM and seams to disapear at around 2500 rpm car is able to 70+ on the motorway so i dont think it is overboost problems going to get it hocked up to vagcom see what happens

  9. #8
    jojo's Avatar
    S3 Drift King!

    Status
    Online
    Join Date
    Sep 2003
    Location
    Solihull, Midlands
    Posts
    25,413
    You could try and drive your car with the MAF unplugged, it will be running with less power than standard, buy should still rev cleanly throughout the rev range. This will test out if the MAF is faulty.



    99' Audi S3(APY) - Brilliant Black Click>>>Going Sideways vid!
    You've got to have a laugh!



  10. #9
    Neutral

    Status
    Offline
    Join Date
    May 2010
    Posts
    65
    this sounds like mine, although i didn't notice anything was wrong as its done it ever since i bought it. what should it hold a decent amount of boost to? mines seems a bit weak after 2.5k?? or am i just being paranoid?

  11. #10
    MURRAYS444's Avatar
    4th Gear

    Status
    Online
    Join Date
    Aug 2009
    Location
    Edinburgh
    Posts
    789
    Air mass meter!

  12. #11
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66
    Quote Originally Posted by lewis88 View Post
    this sounds like mine, although i didn't notice anything was wrong as its done it ever since i bought it. what should it hold a decent amount of boost to? mines seems a bit weak after 2.5k?? or am i just being paranoid?
    mines used to pull like a train and give a nice surge of power up to 3500rpm now power is crap and no turbo after 2300RPM but turbo comes in nicely at 1500 RPM-2000 rpm when i let of the throtle at around 2500rpm i get a dump valve sort of noise

  13. #12
    6th Gear

    Status
    Offline
    Join Date
    Aug 2010
    Posts
    1,540
    if you look at the actual values on the diagnostics while driving the car.... you'll see that the airmass intake figure depending on what bhp the car is will go up tp 850 to 1100 grammes of air per second on full boost. unplug the airmass and the ecu leaves it on a safe 550 grammes per second all the time. unless the airmass is totally ****ed...... unplugging it is not a good test on whether its working or not!
    Last edited by murran; 17th August 2010 at 00:44.

  14. #13
    jojo's Avatar
    S3 Drift King!

    Status
    Online
    Join Date
    Sep 2003
    Location
    Solihull, Midlands
    Posts
    25,413
    Quote Originally Posted by murran View Post
    if you look at the actual values on the diagnostics while driving the car.... you'll see that the airmass intake figure depending on what bhp the car is will go up tp 850 to 1100 grammes of air per second on full boost. unplug the airmass and the ecu leaves it on a safe 550 grammes per second all the time. unless the airmass is totally ****ed...... unplugging it is not a good test on whether its working or not!
    If the car is struggling to go past 2.5k, then unplugging the MAF as a test to see if it effects performance won't harm the car right? I'm not saying it's a full proof way of testing it, but just a way of testing if the fault is MAF related?



    99' Audi S3(APY) - Brilliant Black Click>>>Going Sideways vid!
    You've got to have a laugh!



  15. #14
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66
    i have had a diagnostic check done today and it came up with a fault for the maf sensor the airmass intake figure was low also had the EGR valve checked and it was full of crap and was casueing the valve to stick so i got it cleaned i recomend that everybody should clean thier EGR valves out as it has made a difrance to the car i just need to get a new MAF sonsor

  16. #15
    Turkster's Avatar
    Bro.Paul 2.5TDI Quattro Sport

    Status
    Offline
    Join Date
    Dec 2007
    Location
    Northampton, Northamptonshire, United Kingdom
    Posts
    2,723
    Some good info in this thread,

    My 2.5 TDI is having an small issue, from stand still if you floor it the power is just not there, she takes off at an ok speed, by the time the car has choked to the end of the gear it flys off in 2nd gear a lot better and the turbo kicks is, 3rd,4th, 5th and 6th are there ok,

    I unplugged the EGR valve and wooosh off she goes like a bomb, but pipe that goes onto the EGR valve is not blocked so its classed as leaking? when i block the pipe with a bolt the car takes off ok but not as powerfull, The EGR valve is on 2 years old as iv changed it before, the pipe that connects to the EGR valve is sucking good,

    Do you think it could be the actuator on the Turbo sticking ?

  17. #16
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66
    the valve coulde be sticking have u had it scaned

  18. #17
    Turkster's Avatar
    Bro.Paul 2.5TDI Quattro Sport

    Status
    Offline
    Join Date
    Dec 2007
    Location
    Northampton, Northamptonshire, United Kingdom
    Posts
    2,723
    Quote Originally Posted by anilkumar View Post
    the valve coulde be sticking have u had it scaned
    should be done on sunday

  19. #18
    6th Gear

    Status
    Offline
    Join Date
    Jul 2007
    Location
    London
    Posts
    3,209
    You can block the valve at the manifold side with a thin metal gasket between the matting faces. I have done-it for years or you can reduce the oppening of the EGR valve with vag-com, login code 26262 in basic setings block4. Increase the value eg: 32768 to the highest value the ECU will accept, tipically 33638 or there abouts. The valve will still work within the factory spec but will clog on a much much slower rate(Disclaimer: For Off Road Use Only !). Not every ecu will accept the 26262 login code so if the ECU drops connection with the VCDS then it wont work.
    FOR SALE:
    -Golf mk 5/audi a3 1.6 FSI fuel pump, brand new genuine part boxed + seals
    -audi a3 (1998 to 2003) genuine clutch slave cylinder to fit 1.6 engines BRAND NEW
    -Rear bush press tool to fit new rear axle bushes on Golf Mk3/4, Audi a3/S3, Seat Leon/Toledo, Skoda Octavia mk 1/2 used once

  20. #19
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66
    i have got a new MAF sensor for Ł80 from GFS audi wanted Ł159 fited to the car and it now semms to be fine also had to change fuel temp sensor and temp sensor

  21. #20
    Neutral

    Status
    Offline
    Join Date
    May 2010
    Posts
    65
    ive just heard that sort of dump valve noise on my car at 2.5k. im planning on getting the car diagnostic scanned but before that im going to clean the MAF sensor and EGR valve just incase.
    anilkumar, did your car take a while to warm up? and did it seem slightly better when it was warm? apparently eurospares or europarts do the bosche OEM MAF sensors for Ł36, im just sourcing the other parts now.

  22. #21
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66
    eruo carparts quoted me me Ł120 for a maf did two trips 2 birmingham to coventery over the last 2 days car seems to be fine sum days and then semms to have no boost above 2300k rpm at times restarting the car has no difrance no fault codes coud it be a fault with the N75 dont think it is going im to limp mode car can do 70 +
    Last edited by anilkumar; 29th August 2010 at 20:41.

  23. #22
    Neutral

    Status
    Offline
    Join Date
    Jul 2010
    Location
    Birmingham
    Posts
    66
    Quote Originally Posted by lewis88 View Post
    ive just heard that sort of dump valve noise on my car at 2.5k. im planning on getting the car diagnostic scanned but before that im going to clean the MAF sensor and EGR valve just incase.
    anilkumar, did your car take a while to warm up? and did it seem slightly better when it was warm? apparently eurospares or europarts do the bosche OEM MAF sensors for Ł36, im just sourcing the other parts now.
    it sems ti warm up ok car feels the same when its warm

  24. #23
    5th Gear

    Status
    Offline
    Join Date
    Feb 2012
    Location
    Pie eating land
    Posts
    1,287

    My Social Networking

    Follow ruffrida On Twitter Visit ruffrida's Youtube Channel
    This defo sounds like your vanes are stuck in the turbo, i had a really bad over boost problem with my 110 tdi - 2000 plate, i have taken my turbo to be reconditioned as the vanes where that bad it nearly seized me turbo. Hopefully be all good when i get it back tomorrow.
    Before all this i changed the N75, maf sensor, all the hoses (for nice red ones), and none of it fixed it, made it better but did not fix it.
    You could try the Mr muscle vane cleaner, go on my home page and look under threads started by me, its called how to get more bhp from your tdi ( i think), works awesome for some people, didnt work for mine as it was to far gone.
    B6 1.9tdi Quattro Avant Sport:
    My Build Thread = http://www.audi-sport.net/vb/a4-a4-c...so-begins.html

    Coming soon: -35mm Springs, Colour coded FOG grills, Trip stalk upgrade.
    Wish List; FMIC, BV43 turbo, Bigger Remap, Fat Clutch,Full Stainless, S4 Brakes, 5m mspacers - front, 10mm spacers rear, MFSW.

  25. #24
    5th Gear

    Status
    Offline
    Join Date
    Feb 2012
    Location
    Pie eating land
    Posts
    1,287

    My Social Networking

    Follow ruffrida On Twitter Visit ruffrida's Youtube Channel
    Be nice to know how you got on here bud, as i have replaced me maf sensor, cleaned egr, and blanked it off, all hoses replaced, new turbo and still goes into limp mode in 4th gear at about 2500revs.

    Any ideas guys??
    B6 1.9tdi Quattro Avant Sport:
    My Build Thread = http://www.audi-sport.net/vb/a4-a4-c...so-begins.html

    Coming soon: -35mm Springs, Colour coded FOG grills, Trip stalk upgrade.
    Wish List; FMIC, BV43 turbo, Bigger Remap, Fat Clutch,Full Stainless, S4 Brakes, 5m mspacers - front, 10mm spacers rear, MFSW.

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO