Jonny Chee

Hi all,

Twice over the last few weeks whilst driving, my 2001 Octavia TDi 1.9 has lost a lot of power. Both times after turning the ignition off and back on again the power returns! I noticed the last time it happened that when the power was gone I could not hear the whistle of the turbo but when the power returned the whistle was back as good as new..

Does anybody have any ideas what could be the problem as I am totally confused by this?

Thanks in advance.

cheezemonkhai

Possibly sticky turbo vanes.

Find somebody local with VAG COM or pay somebody to do a diagnostics reading.

If you get an overboost message then the vanes are sticking.

Dealers will tell you this is a new turbo, but if you are handy with a spanner you can clean up the VNT mechanism yourself. Failing that most turbo specialists will be able to do the job just fine.

To avoid this in the future you should get your EGR and intercooler cleaned out at the same time and it can help to change the air filter more often than the recommended 40k. That plus give the car a boot from time to time.

Personally I'd try the italian tune up route (eg warm it up then boot it a bit) and see if this frees the vanes up before visiting the garage.

__________________
Cars make CO2 and trees absorb CO2. By driving your car you're feeding a tree and helping the environment.

ap0gee

According to honestjohn, you could be looking at one of the following:

sticking turbo due to dirty oil;
dirty or faulty mass airflow sensor;
exhaust gas recirculation solenoid valve sticking open;
wastegate valve actuator rod sticking;
faulty throttle switches;
faulty temperature sensor;
loose or leaking brake servo pipe;
turbo boost pipe from fuel pump to turbo;
faulty ECU;
faulty Relay 109 (if it's white it needs to be replaced with a new spec relay coloured grey, costs £11).

The third-last one is particularly common apparently...

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KenONeill

Which engine tune is it? If it's the 110 bhp (TDi), it's almost certainly turbo vanes as Cheezmonkhai says.

Jonny Chee

It is the Ambiente model which I believe is 90bhp?

I have just took it out and 'thrashed' it.....

KenONeill

If it's a 90, which it is, it doesn't have a VVT, so the vanes can't stick!

Jonny Chee

Seems my 'thrashing' yesterday did not do the trick. My car lost power/turbo again today. The three times it has happened have been precisely at the same point, about 5 minutes into my journey to work on the bypass. Again today I pulled over, switched off the ignition, fired it back up and the turbo was fine again for the remaining 30 minutes of my journey!

The turbo on my car was only fitted a year ago by previous owner, I believe it is an Audi turbo and was second hand but in excellent condition. It is also worth noting that my car is an ex company car so has very high mileage (235k).

KenONeill

Can you find the exact model number turbo then? And if there was any other work done?

I've a nasty feeling this may be a mongrel issue.

cheezemonkhai

If they have fitted a VNT turbo to your car it's going to be fun

__________________
Cars make CO2 and trees absorb CO2. By driving your car you're feeding a tree and helping the environment.

KenONeill

Hence the question. I know some of us don't mind that sort of fun, but only when we know what we're letting ourselves in for.