turbo not kicking in

[jimmytk]

My 2001 Octavia 1.9 tdi elegance has started to feel very sluggish the last couple of times I have taken it out. Acceleration is very slow and the turbo does not seem to be kicking in. Once it gets to about 70mph on the motorway it will no longer accelerate. Car has only 90k miles on the clock. Does this suggest a new turbo is needed? I'm hoping not as I can imagine it is rather expensive to replace a turbo. Also, is it safe to use the car with this typeof problem?

[pikpilot]

Many threads on this subject. Search for sticking turbo vanes and also look at Small Engine - VW Audi Seat Skoda TDi PD & diesel servicing specialists in Nottingham. Another symptom of a sticking vane is that if you stop then turn off the engine and restart, performance is reset to normal.

Another possibility is shown in this thread: http://briskoda.net/octavia-i/octavia-diesel-sticky-vanes-maf-sensor-not/160251/ which was a MAF sensor. Simon's problem also occurred at 70mph.

[mbames]

a vag-com check is the first thing to do.

issues could be:

- MAF

- n75

- vacuum leak

- coolant sensor

- VNT issue

Try unplugging the car and taking it for a drive. If the car feels more responsive then the chances are that the MAF is giving duff readings (but still within range) and thus the car performs like a dog.

If you drive down a narrow road with with the windows open can you hear a turbo whistle reflecting back off the walls of the houses?

[bl915]

sorry for jumping in here, but i am actually experiencing similar symptoms.. @mbames - i can hear my turbo whistle really really well especially between buildings, under bridges, next to walls, etc.. i can hear it really well in general, even in an open space.. is this a good or bad thing?

[cliver]

Mass Air Flow sensor (MAF) gives this fault .If it is sticky vanes switching off then on clears condition..temporarily

cliver

[pikpilot]

sorry for jumping in here, but i am actually experiencing similar symptoms.. @mbames - i can hear my turbo whistle really really well especially between buildings, under bridges, next to walls, etc.. i can hear it really well in general, even in an open space.. is this a good or bad thing?

On a previous car (Peugeot-Citroen turbo diesel) at around 90k miles my turbo started to sound like the wail of a police siren as I accelerated. I did about another 5k miles before it became too loud and I replaced it with one from a newer crashed car for £95. I guess it was the bearing in the turbo.

[bl915]

On a previous car (Peugeot-Citroen turbo diesel) at around 90k miles my turbo started to sound like the wail of a police siren as I accelerated. I did about another 5k miles before it became too loud and I replaced it with one from a newer crashed car for £95. I guess it was the bearing in the turbo.

well the thing is it actually sounds really good. haha. its not really like a siren, just a "whispy" / "wooshy" sound. i love it, but there is a serious fluctuation in power. ive done some logging and i am overboosting around 2,000 - 3,000 RPMS (low end torque), but i also have noticed a significant amount of turbo lag, it is not nearly responsive as it used to be. so basically what is happening is its taking longer than usual to kick in, then when it does it overboosts

[mbames]

ive done some logging and i am overboosting around 2,000 - 3,000 RPMS (low end torque), but i also have noticed a significant amount of turbo lag, it is not nearly responsive as it used to be. so basically what is happening is its taking longer than usual to kick in, then when it does it overboosts

If power cycling the ignition when then happens cures the fault for a bit, then you probably have sticking vanes in the turbo. I had to cycle my ignition once this morning on the way to work, and twice on the way back.

In my case, when I get to about 3000rpm you can feel the car backing of acceleration. If you change gear then you sometimes get away with it, but generally it happens the next time you get to around 3000, and then it logs an overboost error and goes into limphome mode. Cycling the ignition causes the car to drop out of limphome mode.

Edited 17 November, 2009 by mbames

[allytech]

Sounds more like an air mass meter problem

[jimmytk]

My car has been driving much better for the past couple of days, there have been no problems at all with the turbo or acceleration in 1st to 4th gears, although sometimes on the motorway it is still struggling in 5th gear when it gets to 70mph and seems to stop accelerating.

Just done a Vag-Com scan and it came up with the following error message, does anyone know what this indicates?

Address 01: Engine

Controller: 038 906 012 CL

Component: 1,9l R4 EDC 0000SG 3359

Coding: 00002

Shop #: WSC 31480

TMBGP21U322588720 SKZ7Z0A1187877

1 Fault Found:

17964 - Charge Pressure Control: Negative Deviation

P1556 - 35-10 - - - Intermittent

Readiness: N/A

[mbames]

oooh, negative dev? normally mine shows a positive deviation - I think! I'll have to check on the PC in the garage and my other laptop for the previous lagcom logs I have.