1.9 TDi 110 Lack of power and boost.

**joe406** · 02-02-2010,07:31 PM

Hi,

My 1998 110 TDi Passat has done 140k and for the past year it has a fault which is annoying to say the least.

When the car is driven hard up a hill and is revved over 3,000rpm it looses power and the turbo seems to cut out. The only way this can be rectified is by switching the engine off then back on again.

I had the Air Flow Meter replaced but this hasn't solved the problem. This problem does come and go though and for a week it can be fine, however, it uses a lot more fuel when it is playing up.

I have looked around and come to the following diagnosis that it is either the Boost Pressure Sensor or the Variable Vane Actuator. A computer is being put on the car later this week to test for fault codes but I dont think it will come up with anything.

I was wondering if anyone on here had some ideas?

Thanks
Joe.

**martin1810** · 02-02-2010,08:37 PM

The code read will probably be 17965 Boost pressure too high. This fault is usually due to the turbo vanes sticking. It could be boost too low, but that seems to happen less often.

**grover** · 03-02-2010,01:13 PM

Hi,

I too have this issue, and after i popped my vagcom cherry last night i got the same code. It came with:

Charge pressure control: positive deviation P1557 35 10 intermittent

Any help?

If it is the vanes, does this mean its new turbo time?

Thanks in advance

Tom

EDIT: I've a PD engined 115bhp sport - after searching i see it could be the vanes, and if i stump up the 99$ to register my version i could get them to clean themselves - is that right?

**martin1810** · 03-02-2010,03:03 PM

A very long hot run will sometimes sort this out. Best option, if it is sticking turbo vanes, is take turbo off and clean it. Sounds hard but it is mostly a nuts & bolts job.

**grover** · 03-02-2010,03:17 PM

Hi Martin,

Cheers for your reply.

I'll take the cover off later and have a good look at the turbo - i can take the opportunity to cover the glow plugs with dw40 while i am there as they're coming out at the weekend if the weather is kind.

Vanes - I would assume these must be part of the turbine - do they replace the fixed wheel?

Cheers

Tom

**Hex69** · 03-02-2010,03:34 PM

http://www.autozine.org/technical_sc...h_engine_3.htm

Scroll down to
Variable Turbine Geometry (VTG)

**creedxup** · 03-02-2010,03:38 PM

My 1998 110 passat used to do exactly the same thing when my aftermarket adjustable power chip was turned up too high, when I adjusted the power down slightly, the problem never re-occurred.