Help please Turbo problems

[bigmikeyoyo]

Hi,
My car is an 02 A4 TDI 130 with 152k on the clock. Took it to England a few weeks ago and on the way up the M5 it lost power and spluttered black smoke everywhere. Intercooler was broke, limped it up the boat with no turbo and got it home. Replaced intercooler and still wasnt right so replaced EGR valve seemed to go ok apart from a noise from the turbo area which my friend a mechanic said was the wastegate and nothing to worry about. Wife just come home and car is running with no turbo again, showing error code 17965 when I scanned it. Anyone any ideas, is it the N75 valve that I've read about or is the turbo just done, if thats the case does anyone want to buy the car as I'm just about fed up with it. Thanks in advance for any replies,
Mike

[arman123]

Your turbo is overboosting and going in to limp mode most likely the turbo vanes are clogged with carbon you need a new turbo or recon unit you can check to see if the actuator on the turbo is moving freely by using a hand held vac pump

[bigmikeyoyo]

Your turbo is overboosting and going in to limp mode most likely the turbo vanes are clogged with carbon you need a new turbo or recon unit you can check to see if the actuator on the turbo is moving freely by using a hand held vac pump
Thanks for the reply , is that the noise Ive been hearing then ? I checked the turbo a few days ago when changin the Egr valve and it seemed fine no play and vanes were turning ok but i think your right and its fupped, listened to it again there and theres a very slight whistle which I dont think is a good sign. Is it worth taking the turbo off and cleaning it out?

[arman123]

You could have a go some people have used me muscle on the hot side of the turbo to remove the carbon the put it thorough the egr pipe to the hot side of turbo and let it sit a few hours and wash it out with some brake cleaner but if I were you I would just replace it with a good recon unit or better get your reconditioned.

[bigmikeyoyo]

You could have a go some people have used me muscle on the hot side of the turbo to remove the carbon the put it thorough the egr pipe to the hot side of turbo and let it sit a few hours and wash it out with some brake cleaner but if I were you I would just replace it with a good recon unit or better get your reconditioned.
Ok thanks mate will start searching for who's best / cheapest for recon units, is the car ok to drive?

[arman123]

To and from shops and local yes but any overtaking on motorway no it will be dangerous if it event to limp mode

[bigmikeyoyo]

To and from shops and local yes but any overtaking on motorway no it will be dangerous if it event to limp mode

OK mate thanks, I just checked the turbo again and theres no play in it and the vanes appear to be moving freely, dunno what to do tbh:confused:

[arman123]

25654

You our can't check the vanes just by looking at the turbo you can only see if the actuator is moving freely it's the rod in the middle of the turbo with the vac pipe attached to the round shiny thing

[bigmikeyoyo]

25654

You our can't check the vanes just by looking at the turbo you can only see if the actuator is moving freely it's the rod in the middle of the turbo with the vac pipe attached to the round shiny thing
So when I took off the air pipe into the turbo from the airbox and put my fingers in and can feel the fan like metal blades they arent the vanes? They are moving freely. Put it all back together again and the turbos working again however if I have it sitting idling and give it a high rev you would think the engine is about to conk out, vacuum issue?

[arman123]

No there not the vanes have you had it scanned with vcds yet

[bigmikeyoyo]

No mate not yet but will do on Monday , i'll not take up any more of ur Saturday night and appreciate your help thanks

[pauldazzle]

Mr Muscle fix worked for me, & still fine 45k later.

[bigmikeyoyo]

Thanks guys,
Was out working at it today again as I'm not convinced its the turbo as there is boost until 3000 rpm before limp mode kicks in, ignition on /ignition off and its fine again.
On looking at the engine I noticed that the actuator arm on the egr was not moving at all and on removing the vacuum pipe from it there is no vacuum at all. I f I disconnect the pipe from the N75 valve and suck it the arm moves fine so its not it. Does this mean the N75 valve is the problem, any advice greatly appreciated,
Mike

[arman123]

you need to scan it with vcds see what codes you are getting if its positive deviation then the turbo is over boosting if its negative deviation then you might have a boost leak somewhere my moneys on the turbo

[bigmikeyoyo]

hi Arman, yea fair enough but what about the lack of vacuum to operate the egr, is that the fault of the turbo? I find it strange that the turbos fine then I change the egr valve and intercooler and straight away the turbos faulty?

[arman123]

Like I said mate scan is a must then go from there you could throw parts at it all day.
Have a read of this info
Diagnosing and Fixing Limp mode for A4 1.9TDI [low power troubleshooting] - TDIClub Forums (http://forums.tdiclub.com/showthread.php?t=179589)

[arman123]

hi Arman, yea fair enough but what about the lack of vacuum to operate the egr, is that the fault of the turbo? I find it strange that the turbos fine then I change the egr valve and intercooler and straight away the turbos faulty?

Take the egr pipe off plug it block it with something like a screw and take it for a drive see if the turbo goes into limp mode