Cupra TDI turbo late boosting

Discussion in 'TDi - SEAT Diesel specific topics' started by kevin_w90, May 6, 2010.

  1. kevin_w90

    kevin_w90 Guest

    Hello, First time posting on the diesel forum :). Right, the car feels dead up until about 3k and the turbo kicks in with alot of boost. As yous will be aware it normal boosts about 2-2.5k and there is a decent amount of power before the turbo.

    Had it into a garage the other day, it read boost pressure. Its not vag com but it was the best they had at the moment. Its going to seat on monday but last thing i want is a new turbo when it still works just not at the right time. It sounds fine the car, not so much of a turbo whistle right enough but thats becasue its not kicking in early.

    I had the wastegate cleaned and it was really built up with carbon, could this be the vains clogged also? Its basicaly happended all of a sudden, no real build up too it, just one day I started it upafter work and it started.

    Had the maf off and had a little run without it and no difference. Really confusing and annoying me.

    Any help would be really great.

    Thanks
    Kevin
     
  2. JPS3290

    JPS3290 Dirty Diesel

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    You checked boost pipes for splits?

    Mine did something similar and made a strange 'flapping' kind of noise when accelerating. Turned out that the pipe coming out of the turbo back into the engine (best way I can describe it) had been rubbing against a metal clip (crap design) and created a 1 inch split on the bottom of the pipe.

    Duct taped it up until they ordered me a new one under warranty and was fine. It showed the same symptoms of not boosting as much lower down and also bit more smoke out of the exhaust.
     
  3. Muttley

    Muttley Catch that diesel!

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    kevin_w wrote

    I had the wastegate cleaned and it was really built up with carbon, could this be the vains clogged also? Its basicaly happended all of a sudden, no real build up too it, just one day I started it upafter work and it started.

    Er. This is a PD engine with a VNT (i.e. variable geometry, with vanes in the exhaust turbine) turbocharger. It doesn't have a wastegate.

    What's the location of the bit that you had cleaned? If its under the silver saucer at the back of the engine compartment, on the inlet manifold, then its the EGR valve. They can clog up with a sticky sooty deposit formed when hot sooty exhaust hits the oil vapour from the crankcase ventilation that gets pumped into the inlet charge.

    Sooted-up EGR doesn't necessarily mean sooted-up vanes, but it is more likely than not. What mileage has the engine done, and is much of it at low-to-medium speeds i.e. in slow-moving traffic queues?


    Had the maf off and had a little run without it and no difference. Really confusing and annoying me.

    No difference with and without the MAF indicates a failed MAF.
     
  4. rod the sod

    rod the sod Senior Member

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    Hey i had a similar problem with my new hybrid pd turbo! The VNT was set up wrong and i was having major boost @ about 3k! As for as i kno this only really goes wrong if you have adjusted to fiddlied with the turbo - unless you have a faulty one.

    With the vains being faulty the turbo should kick in then feel like it boosts again at a higher rev range.

    i would check for small boost leaks before you start thinking about playing with more expensive stuff!
     
  5. kevin_w90

    kevin_w90 Guest

    Cupra Turbo

    Ahh i see, sorry the egr valve it was, was the bit up beside the silver plate bit. (not very good with engineslol). The car has done 72000 miles. Up until November the car was getting about 500 miles a week with long open roads. Now its main dirve is a 3 miles too work and back but no real stop starts as I live in the country and my work isn't in a town. So cars not even doing 100 miles a week now.

    Hopeing its just needing a clean an not a new turbo, got it booked into a dealer on monday but dont want them to go replace the whole turbo when it is still boosting.

    Is the turbo down the back of the engine under the egr valve? Ahh the maf may be gone since it never made a difference? When it was pluged in the code histroy ready maf short (thought that was when I unpluged it) and had a boost error.

    Thanks
     
  6. Muttley

    Muttley Catch that diesel!

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    If unplugging the MAF makes no difference to the way the car drives, then the MAF is shot.
     
  7. S3 AKR

    S3 AKR livin' the dream!!!

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    Not sure about the boost error you mention, but the "MAF Short" will stay in the DTC list till cleared by vag-com.
     
  8. MJ

    MJ Public transport abuser

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    it will only say {mass air flow sensor G75 - open circuit} denoting that its been unplugged.
     
  9. S3 AKR

    S3 AKR livin' the dream!!!

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    I was assuming as MJ quotes above, that this was the error logged.

    If you get any logs then its best to keep them and search the forums for info on them. There's a load of info available, particularly on here, the UK-MKIVS forum, Briskoda and Ross-tech - all pretty good and reliable sources of info. (Plus MJ seems to know what he's on about from what I've seen :thumbup:)
     
  10. alexcuprapd160

    alexcuprapd160 New Member

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    this thread is years old but i have the same question with the exact same issue as the first post and wondered what the solution was?
     
  11. cheshire cat

    cheshire cat Full Member

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    check it's holding vac on the line from the "valve block" to turbo if OK then check for actuator movement on the turbo
     

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