florinman@gmail.com wrote:
> On Jun 7, 10:32 pm, Tony <tonyjNOS...@NOSPAMvisi.com> wrote:
>> florin...@gmail.com wrote:
>>> On Jun 4, 10:30 pm, Tony <tonyjNOS...@NOSPAMvisi.com> wrote:
>>>> florin...@gmail.com wrote:
>>>>> Hi everybody,
>>>>> - why the car is producing a rattling noise while decelerating in the
>>>>> air filter area? I believe that it is relared with the "cut-off" valve
>>>>> but how can I decide it is broken, what experiments should I make,
>>>>> what data in VAG-COM should I follow?
>>>>> - why is the rpm droping when I take the foot off the pedal?
>>>>> - is the new debitmeter broken, or is the old one but in such manner
>>>>> that it hides some of the car's vices?
>>>>> - what do you think I should do to solve the problem or make it clear?
>>>> The debitmeter that you refer to is not a term that I have heard in the
>>>> US but a Google seems to indicate that it is the Diverter Valve that you
>>>> are referring to. The DV may be at fault causing boost problems but
>>>> probably not the cause of most of your issues.
>>>> A rattle under deceleration is often associated with a failed Waste Gate
>>>> actuator which is part of the turbo but can be replaced separetly for
>>>> about $180 US parts cost. If this is the problem you would experience
>>>> loss of boost underaccelerationbut it would not be the reason that you
>>>> are getting codes.
>>>> I would guess that you had a loose connection of the O2 sensor. Crimped
>>>> wire connection are preferred over soldered when replacing with generic.
>>>> I don't remember you saying that you replaced the MAF. If not that is
>>>> the first thing I would suggest and then see what codes you get. The MAF
>>>> can be cleaned but replacing it is a more certain fix.
>>> All appologies! By debitmeter I was reffering to MAF!
>>> I have placed back the old MAF and the errors dissapeard. The
>>> turations stilldropthough... and the sound is still scratching my
>>> nerves.
>>> So you are saying that is the "Waste Gate Actuator"... Is this the
>>> termaudiuses as well for this part? Well I will look for this part,
>>> see where is located but
>>> meanwhile I have ordered a Diverter Valve because someone told me that
>>> the sound can be associated with DV. What do you think about that?
>> Good that replacing the MAF corrected the codes.
>>
>> "Waste Gate Actuator" is the term that is used in the US and I would
>> guess most other English speaking countries. It is an assembly that is
>> attached to the side of the turbo and is usually considered a part of
>> the turbo but can be changed separetly. Replacing it requires remocing
>> the turbo. I was just guessing that this might be your problem. Be sure
>> to diagnose the problem before spending money and time on it.
>>
>> A failed waste gate actuator can be diagnosed visually. With the engine
>> off, look down the exhaust side of the engine and see the turbo. Between
>> the turbo and the engine you will just barely be able tyo see a shiny
>> steel rod running forward and back. That it the actuator rod. Use a
>> stick to reach down to push on the shiney rod Try to move it back and
>> forth. If it moves at all it is bad otherwise it is probably fine.
>>
>> Changing the DV is a good idea and may help. It would have been a good
>> idea to pressure test the system for leaks and observe boost with a gage
>> to see if you have a problem with it before buying parts.
>>
>> Let us know your progress.
>
> Hello,
>
> Well I have finally replace the DV. The resoults are good: the noise
> dissapeared or at least is hardly noticeable and the rpm drops are now
> smaller and rarely appear.
> But... to be able to use the car untill I got the DV I have put back
> the old MAF and I have returned the new one (I descriebed the problems
> related with the new MAF in my first post). Since then I experience a
> engine power loss. I am still hearing the turbo but the car lacks
> power.
> Please see the VAG-COM log file in which I have also generated a
> graph: http://www.yousendit.com/download/WF...YTIrV3cwTVE9PQ
> What I suppose is that there is a problem with the turbo pressure
> because the actual pressure (@Intercooler) (with the red color), is
> allways less than requested presure - yellow. In fact the pressure
> only incerases if I press at once and very hard the gas pedeal. If I
> press it gredualy nothing happens. Is this normal? With blue are the
> rpm. With green are the verry slow values recorded by the MAF. What do
> you think about these measurements?
>
It still sounds like a problem with the waste gate actuator and may be
combined with a vacuum leak.

 

> It still sounds like a problem with the waste gate actuator and may be
> combined with a vacuum leak.
Well, I have started to read about the waste gate actuator and at this
location: Washttp://en.wikipedia.org/wiki/Wastegate and I have seen
the last paragraph - "Wastegate chatter myth" which seems to completly
explain the noise I experience. Long story short, it says that the
turbine makes the noise but the cause is DV not WGA.

Anyway, I will check the turbo system, including WGA.

If you have any other ideea please tell me. Is possible to experience
the above issues because of the pressure sensors?

 

> It still sounds like a problem with the waste gate actuator and may be
> combined with a vacuum leak.
Well, I have started to read about the waste gate actuator and at this
location: Washttp://en.wikipedia.org/wiki/Wastegate and I have seen
the last paragraph - "Wastegate chatter myth" which seems to completly
explain the noise I experience. Long story short, it says that the
turbine makes the noise but the cause is DV not WGA.

Anyway, I will check the turbo system, including WGA.

If you have any other ideea please tell me. Is possible to experience
the above issues because of the pressure sensors?

 

> It still sounds like a problem with the waste gate actuator and may be
> combined with a vacuum leak.
Well, I have started to read about the waste gate actuator and at this
location: Washttp://en.wikipedia.org/wiki/Wastegate and I have seen
the last paragraph - "Wastegate chatter myth" which seems to completly
explain the noise I experience. Long story short, it says that the
turbine makes the noise but the cause is DV not WGA.

Anyway, I will check the turbo system, including WGA.

If you have any other ideea please tell me. Is possible to experience
the above issues because of the pressure sensors?

 

> It still sounds like a problem with the waste gate actuator and may be
> combined with a vacuum leak.
Well, I have started to read about the waste gate actuator and at this
location: Washttp://en.wikipedia.org/wiki/Wastegate and I have seen
the last paragraph - "Wastegate chatter myth" which seems to completly
explain the noise I experience. Long story short, it says that the
turbine makes the noise but the cause is DV not WGA.

Anyway, I will check the turbo system, including WGA.

If you have any other ideea please tell me. Is possible to experience
the above issues because of the pressure sensors?

 

florinman@gmail.com wrote:
>> It still sounds like a problem with the waste gate actuator and may be
>> combined with a vacuum leak.
> Well, I have started to read about the waste gate actuator and at this
> location: Washttp://en.wikipedia.org/wiki/Wastegate and I have seen
> the last paragraph - "Wastegate chatter myth" which seems to completly
> explain the noise I experience. Long story short, it says that the
> turbine makes the noise but the cause is DV not WGA.
>
> Anyway, I will check the turbo system, including WGA.
>
> If you have any other ideea please tell me. Is possible to experience
> the above issues because of the pressure sensors?
>
When I lost the WGA in my '98 A4 1.8TQM It lost almost all of the boost
and it rattled. I could also rattle the rod with a stick.
We pulled the K03 out and verified that the WGA was bad because it had
no resistance. We replaced the WGA from a spare K03 and the problem was
solved and boost was back

Your issue may well be different.

 

florinman@gmail.com wrote:
>> It still sounds like a problem with the waste gate actuator and may be
>> combined with a vacuum leak.
> Well, I have started to read about the waste gate actuator and at this
> location: Washttp://en.wikipedia.org/wiki/Wastegate and I have seen
> the last paragraph - "Wastegate chatter myth" which seems to completly
> explain the noise I experience. Long story short, it says that the
> turbine makes the noise but the cause is DV not WGA.
>
> Anyway, I will check the turbo system, including WGA.
>
> If you have any other ideea please tell me. Is possible to experience
> the above issues because of the pressure sensors?
>
When I lost the WGA in my '98 A4 1.8TQM It lost almost all of the boost
and it rattled. I could also rattle the rod with a stick.
We pulled the K03 out and verified that the WGA was bad because it had
no resistance. We replaced the WGA from a spare K03 and the problem was
solved and boost was back

Your issue may well be different.

 

florinman@gmail.com wrote:
>> It still sounds like a problem with the waste gate actuator and may be
>> combined with a vacuum leak.
> Well, I have started to read about the waste gate actuator and at this
> location: Washttp://en.wikipedia.org/wiki/Wastegate and I have seen
> the last paragraph - "Wastegate chatter myth" which seems to completly
> explain the noise I experience. Long story short, it says that the
> turbine makes the noise but the cause is DV not WGA.
>
> Anyway, I will check the turbo system, including WGA.
>
> If you have any other ideea please tell me. Is possible to experience
> the above issues because of the pressure sensors?
>
When I lost the WGA in my '98 A4 1.8TQM It lost almost all of the boost
and it rattled. I could also rattle the rod with a stick.
We pulled the K03 out and verified that the WGA was bad because it had
no resistance. We replaced the WGA from a spare K03 and the problem was
solved and boost was back

Your issue may well be different.

 

florinman@gmail.com wrote:
>> It still sounds like a problem with the waste gate actuator and may be
>> combined with a vacuum leak.
> Well, I have started to read about the waste gate actuator and at this
> location: Washttp://en.wikipedia.org/wiki/Wastegate and I have seen
> the last paragraph - "Wastegate chatter myth" which seems to completly
> explain the noise I experience. Long story short, it says that the
> turbine makes the noise but the cause is DV not WGA.
>
> Anyway, I will check the turbo system, including WGA.
>
> If you have any other ideea please tell me. Is possible to experience
> the above issues because of the pressure sensors?
>
When I lost the WGA in my '98 A4 1.8TQM It lost almost all of the boost
and it rattled. I could also rattle the rod with a stick.
We pulled the K03 out and verified that the WGA was bad because it had
no resistance. We replaced the WGA from a spare K03 and the problem was
solved and boost was back

Your issue may well be different.