speed problem with the A4 TDI 1.9 AVANT 2001

[SAID]

Hi there!
the engine of car keeps cuting down each time i try to accelerate a bit more or go above 60mph!! the engine loks like if it's getting stuck or something! the only way to get the car back to normal is to stop and switch off the engine and then restart it again!! that does'nt happen all the time though, well once in a while( every 4 weeks or so)
I suspect the turbo, because the puch it gives to the car normaly does'nt happen when the problem above starts.
I took the car to a garage and they adviced me to keep driving it till it breaks down then they'll find out what's causing this!!!
I must say that lately the problem starts to happen quite often, more then ever before!
please if you have any idea what's causing this let me know.
Many thanks.

[Eshrules]

Hi there!
the engine of car keeps cuting down each time i try to accelerate a bit more or go above 60mph!! the engine loks like if it's getting stuck or something! the only way to get the car back to normal is to stop and switch off the engine and then restart it again!! that does'nt happen all the time though, well once in a while( every 4 weeks or so)
I suspect the turbo, because the puch it gives to the car normaly does'nt happen when the problem above starts.
I took the car to a garage and they adviced me to keep driving it till it breaks down then they'll find out what's causing this!!!
I must say that lately the problem starts to happen quite often, more then ever before!
please if you have any idea what's causing this let me know.
Many thanks.

suspect turbo issues... could be sticky turbo vanes or VNT mechanism... try a search on the forum for power loss/turbo issues.

[ini]

If you have a non-PD 110 engine and have overboost problems which reset when you cycle the ignition (turbo cuts out under load, up hills, motorway etc) the usual suspects are:

MAF - mass airflow meter could be fouled or worn, try cleaning it by squirting brake cleaner or similar onto the element inside. Or replace.

Timing - if your timing is too retarded it can cause overboost symptoms due to reduced fueling, especially if your car is due for a belt change.

VNT mechanism - as stated above, the mechanism for angling the variable vanes can gum up. It is recommended not to drive to sedately in a TDI with a VNT, take your car out for a good long blast at high revs.

EGR - your exhaust gas recycling valve may be gummed up and not opening/closing properly.

Boost/Boost control leak - Check all the hoses and tubing, especially the small diameter tubes on the boost control system for leaks or blockages. Check intercooler hose etc for wear or leaks.

Inlet manifold - your inlet manifold could have a thick layer of crud built up inside it, which will mess with reported manifold pressure.

N75 - the variable valve that controls your vnt could be worn or blocked.

Your overboost is most likely MAF or timing related.

[SAID]

Hi there...
I checked all the pipes and the MAF...all in good order.
I went to the Audi specialists with the code the computer gave me and they said that there's an air leak somewhere( to do with the pipes which are attached to the turbo) but i could'nt find any!!
the car still have the same problem, i went to Oxford the other day and it happened on the way there and i carryed on driving like that all the way ( maximum speed i could reach 85mph ) with 4 people on board!!!!
but on the way back the car was fantastic!!
Well! im still investigating.. thank you very much for you're help, and i'll keep you updated.
take care.
Said