1.9TDI Power Loss after long journys till car stoped n started again

[Oliver Twisted]

After driving my Octavia on the moterway sometimes i find that uphill it sometimes struggles for revs and after coming off the moterway its almost as if the turbo aint kicking in but if i stop turn the car off and back on again its fine

if anyone has any idea whats up please let me know ,cheers

Olly

[Gizmo]

Sounds like the turbo has over boosted, the car will then go into limp mode to get you home.

I would be interested in the cause of this also, as a car i have just VAG-COM'ed is suffering from the same fault.

We have narrowed it down to be either the turbo's variable vanes or linkage sticking??

[cjb]

The other possibility is a sticky N75, but there's a good chance it's the turbo.

[KenONeill]

I'd actually think the N75 is more likely; overboost problems tend to affect the 110 more than the 90 or 130.

[Gizmo]

Is there any way to positively identify the problem as the N75?

My scan was:

Monday,19,November,2007,19:30:05:22041

VAG-COM Version: Release 704.1

Data version: 20071016

Chassis Type: 8D - Audi A4 B5

Scan: 01 02 03 08 15 16 17 25 35 37 45 55 56 57 67 75 76 77

-------------------------------------------------------------------------------

Address 01: Engine Labels: 038-906-019-115.LBL

Part No: 038 906 019 BR

Component: 1,9l R4 EDC 0000SG 1064

Coding: 00002

Shop #: WSC 06335

1 Fault Found:

17965 - Charge Pressure Control: Positive Deviation

P1557 - 35-00 - -

Readiness: 0 0 X X X

This is on a 2000 (W reg) 1.9 TDi 115 Audi A4.

[mbames]

iirc when I had a description like that the garage suggesting the MAF, and then the N75, and then turbo.... :-(

[VRStu]

N75 is the easiest and cheapest to try first if not then it's probably a turbo strip and clean.

[Octygone]

My pd 130 does exactly the same ...uphill..and...no turbo .....switch off ...restart and it's fine.........let me know what you find

[Gizmo]

MAF has already been done recently, so N75 is the next step we will try,

one reason why we thought it could be a sticking linkage is when it went into limp mode, the engine was revved up (whilst stationary) but it took a second or two to drop down again.

Would a faulty N75 also cause that to happen?

[VRStu]

N75 controls the actuator that moves the vanes.

Did you try moving the vanes on yours Rob?

[mbames]

if your going to try doing that remember to disconnect the vacuum pipe from the n75 first. I tried moving mine and they were some hard to move.....

[Octygone]

N75 controls the actuator that moves the vanes.

Did you try moving the vanes on yours Rob?

Not got it at the moment I sent it back to the bodyshop to put all the things they did to it right........just don't get any crash repairs done at BP Rolls in Andover

[VRStu]

Ahh - It's all clear now.

Did the turbo issues start when you got it back?

[BigGar]

Had the same symptoms and fault code (17965) 2 months ago. 110 TDI. It was a sticky turbo.

[Octygone]

Ahh - It's all clear now.

Did the turbo issues start when you got it back?

it has been going on for a couple of months now .....just learnt not to boot it up hill, so I am guessing the vanes are sticking full on and over boosting .....and it's still under warranty

[greg123]

It can affect the 130, just they are newer.

The 90 has a conventional wastegate turbo, hence it doesn't have the vanes issue.

I'd actually think the N75 is more likely; overboost problems tend to affect the 110 more than the 90 or 130.

[greg123]

No need to disconnect, the vacuum is NOT applied till the engine is started. You shouldn't be fiddling with it when it's running.

if your going to try doing that remember to disconnect the vacuum pipe from the n75 first. I tried moving mine and they were some hard to move.....

[greg123]

It is VERY easy to see if your turbo vanes are moving, you don't even need vag com.

Get a torch and stand by the OSF wheel. Shine it down by the plastic pipe to the turbo and manifold. Get an eye on the turbo and in the middle you'll see a little arm and possibly see the circlip on it. Now have an assistant start the car.

When started the arm will move FULLY DOWN, nearly an inch (haven't measured, but at least 1.5-2cm, if it just moves a bit or just a cm, it's bust).

Turn it off, the arm will move FULLY UP.

If that isn't happening you can investigate further, an easy kick start is to apply vacuum to the tube that goes to the turbo from the N75. I suspect you will not get full arm movement, but if you do, move on to the N75.

I highly recommend getting the car fault scanned and if an overboost related code is evident look at a graph of requested/actual boost in vag-com. This way you KNOW.

I have just fixed a COMPLETELY seized one of these, the owner taking it easy up hills just made it get progressively worse as the less he used it the more it seized up, it's a vicious circle.

I also suggest if you don't want it happening again you fix the design flaws by mechanically disabling the EGR, re-routing the breather and changing gear between 2.5-3k as a rule, not 'lugging' the engine so the turbo control has to regularly exercise to control boost and thus stay clean.

Greg.

[ric04vrs]

i cleaned the vanes on a turbo recently , worked for a bit , but then limp mode started to re-occur , P1557 fault code , new turbo was fitted in the end , has been ok since

[greg123]

How did you clean them, what method? If properly cleaned it is as new, unless you have actuator issues (failure/faults or incorrect adjustment) it should last as long as a new one.

i cleaned the vanes on a turbo recently , worked for a bit , but then limp mode started to re-occur , P1557 fault code , new turbo was fitted in the end , has been ok since

[mbames]

My car does not log anything, but definately seems to be down on power.... any ideas for that!?

[greg123]

Log anything? I'm talking about using the diagnostic software on a laptop and logging requested vs actual boost. Down on power but not going into limp home could be all sorts, have you had your inlet manifold cleaned, the maf checked/replaced and the timing checked wiht a computer?

[KenONeill]

Matt has VAGCom. What he doesn't have is a logged fault code from a down on power TDi110.

He's tried cleaning the manifolds, replaced various sensors, and I imagine doing a throttle body alignment.

[mbames]

I used to get the the overboost error (shortly after I got the car), and since then I have changed the MAF, n75, and turbo (and coolant sensor). The car has only once ever gone into limp home mode (refused to go over 50mph in any gear), but even then did not log anything. More recently I have tried cleaning the MAF as well, and a nice new air filter. Also cleaned the EGR (Index of /briskoda/20070409_egr)

I seem to hear a bit of a turbo whistle, low down in the rev range - 1500 -> 2000 and after that it seems to go. Sometimes a get a slight stutter from the car around the 2000rpm mark (generally just once in the morning when the car is cold).

I tried to depress the control arm on the turbo and it seemed quite stiff, but I have no idea how free/still it should be? Seemed to be a layer of oil in the intercooler hoses, but nothing major.... (not a river or anything like that!) Car does consume some oil though. I am on variable servicing getting around my expected 30k intervals.

Not done a throttle body alignment - not sure how?

Cheers!

[greg123]

Unless the ecu is faulty there HAS to be a fault code if it's going into limp home. Limp home in a 110 should get 70mph so something is really wrong if you can only get 50 in limp.

Can you log requested vs actual boost in VAG-SCOPE please and press pause after a few full throttle runs from 1.5-4.5k and let us have a look at a screenshot of the picture?

Also can you let us know if the engine will rev to over 5k revs on full throttle in nuteral. If it won't go over 4.5k replace the MAF.

Greg.