Seat Alhambra - Power issues

[Justo]

Guys

I am having some power problems with a seat alhambra. 1.9TDI engine and the boost does not seem to be coming on on the turbo. I have checked all the pipes around the turbo and all seems ok. The VAG Com fault code is saying it is a pressure deviation - on the live data the MAF Values ar all over the place ( nowhere near the specified values) and the injected quzntity is n ot as is should be either.

Having tried changing the two solenoids at the bulkhead and getting no response and changed the MAF I am now low on ideas

Any help much appreciated?

TIA

[s2driveruk]

check the vacuum hoses and fully inspect the whole of the pipework on the intake as its either a boost leak or something like the N75/WGFV could be toast too.

What kind of characteristics does it provide when driving, is it basically flat as a pancake on boost or is there any violent stuttering etc?

Cheers
David

[Justo]

Hi David

Thanks for the advice - i have checked the pipes and all looks ok.

What are the valves you are referring to?


TIA

Justin

[odyssey2200]

Pressure variation between target fuel pressure (in ECU Map) and that being achieved at the rail.

Change the fuel filter.

[iqbal sheryar]

Hi i have a Seat Alhambra 1.9TDI,I am having loss of power issues I have replaced the Mas AirFlow Sensor then the turbo boost control valve but i still have the same problem,When it gets to 50MPH it goes into limp Mode,Is there anything else i can check or do,It's becoming a pain now and dont want to drive the car anymore just because of that problem.

Any help and advice would be appreciated.

[odyssey2200]

Have you changed the fuel filter?

[iqbal sheryar]

changed that today but it's still the same?

[odyssey2200]

look atthe turbo actuator and check that the operating arm is still attached.
I have seen the shaft fall off the waste gate actuator.

You get no boost so the engine sees a fault

Do you know what fault codes you have stored?

[iqbal sheryar]

it was showing mas air flow sensor whic i've changed,Turbo boost control positive deviation,(boost control valve changed)

[odyssey2200]

iqbal sheryar said:

it was showing mas air flow sensor whic i've changed,Turbo boost control positive deviation,(boost control valve changed)

there is a rubber pipe that goes from the Turbo control valve to the waste gate actuator.

Is it kinked or split?

check the wiring to the control valve

can you get hold of a mitie vac pump?

remove the pipe at the control valve end and apply a vacuum.

Does the turbo waste gate opperate correctly?
the waste gate is operated by a diaphragm opperating a rod
The rod is held onto the waste gate by a small pin with an R clip or split pin.

Over time the split pin rusts, falls out and the daiphragm is no longer doing anything.

[iqbal sheryar]

Thanks Mate

I'll try what you have suggested,Thanks very much for your advice much appreciated.

[iqbal sheryar]

tried every thing but to no avail,Any other ideas please.

[Silver940]

Variable vanes in the turbo sticky, causes over boost and then limp mode. Some useful info and links to a cleaning product here: http://uk-mkivs.net/forums/p/230403/1483134.aspx

[Tame Technician]

Turbo overboost is what you are having, is very common.

Must be loads of thread about it on here and other forums.

As a turbo is the fix you need to know thats what it is.

To comfirm check MVB 11 specified boost pressure should be arround 2300mb (1.3 bar boost) and you will find the actually is more like 2600mb (1.6bar boost) which is too much. To prevent turbo and engine blowwing up the ECU puts the car into limp home mode.

Also see thread on turbo cleaner.

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[iqbal sheryar]

Hi anyone know where the N75 boost regulation valve is on a Seat Alhambra 1.9TDI 2002?
Just put my car on a VAG-COM diagnostic and it reavealed code 17957 Boost Pressure Control Valve Open Or Short To Ground ,Is this the same valve as the boost control valve?

Any ideas the car is driving me mad litteraly?

Edited by iqbal sheryar on Friday 3rd September 00:49

[iqbal sheryar]

does anyone know how many N75 valves there are on a Seat Alhambra 1.9TDI 2002.

[iqbal sheryar]

Hi i cleaned the turbo with Innotec checked all pipe work checked for leaks etc none seen,Really don't know what else to try checked the rod acutator but it's stiff can not be moved by hand,

Any ideas??

[martin mrt]

iqbal sheryar said:

Hi i cleaned the turbo with Innotec checked all pipe work checked for leaks etc none seen,Really don't know what else to try checked the rod acutator but it's stiff can not be moved by hand,

Any ideas??

There is your problem, the actuator should have some resistance but it can easily be moved by hand

[iqbal sheryar]

Hi Martin
The acutator is spring loaded should it move by hand?I thought it was hard because it probably moved by pressure etc,The Rod has no play in it at all,What can i do to sort the problem out?


Thanks

[iqbal sheryar]

Hi just and update had a new Turbo fitted today and guess what that was the culprit all along,Drove back from the turbo specialist and it was a pleasure to drive.

I would just like to say a big thanks to all who advised.