Hi everybody,

Please take a little time for my rather long story, but consider the
fact that I' am struggling with this matter for more than a year.
I've bought a Audi TT, 1.8 Turbo, 225 HP from 2000, and soon I have
discovered that the turbine (turbocharger) is broken - was throwing
oil in the exhaust system and the effect was a black smoke.
I've changed the turbine, then because VAG-COM reported a error I've
changed the Lambda oxygen sensor everything was OK in respect with the
VAG-COM, or at least I got no more errors.

Then I have noticed ( I don't remember if this happend before I
changed the turbine) this strange behaviour: whenever I relase too
suddenly the throttle pedal I hear a noise in the air filter area
(some kind of rattling) and the engine rpm drop dangerously to a 400 -
600 rpm. Sometimes in slow speed corners the engine stops.

For this I have changed the throttle body with a new one, after many
calibrations and cleanings - no difference.

Recently I have changed the debitmeter with a new one and everything
got crazy. First the car worked almost as before - with a small lack
of power when I begun to press the acceleration pedal.
When I stoped after few kilometers I received the error:


Control Module Part Number:
Component and/or Version: 1.8L R4/5VT 0001
Software Coding: 05710
Work Shop Code: WSC 00000
1 Fault Found:
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-00 - - - Intermittent

Then I cleared this error, made another few kilometers and I got:


Control Module Part Number:
Component and/or Version: 1.8L R4/5VT 0001
Software Coding: 05710
Work Shop Code: WSC 00000
1 Fault Found:
16514 - Oxygen (Lambda) Sensor B1 S1: Malfunction in Circuit
P0130 - 35-10 - - - Intermittent

I cleared also this error, I have callibrated the throttle body and I
got again the Lambda error.
I have cleared again the Lambda error and then the car became not
stable when I started it. It didn't start at the first few tries, I
got a huge rpm variation, I got explosions in the exhaust etc...

I had to disconnect the debitmeter (pulled of the power cable) and the
car worked different in the sense that it was the first time I didn't
experienced rpm drops, although the noise in the air filter area was
still persistent. But, I couldn't go over 3500 rpm - it was
clear that this was not the fix.

In the next morning I have connected the debitmeter back, got
difficulties when I tried to start the engine but I have hepled the
engine to start by pressing hard the throttle pedal. Whenever the
engine passes the first phase, with the acceleration help it goes to a
"normal" behaviour.

Because I got again the Lambda error I have put it out and clean it,
although it was allready clean. From then on I received no more
Lambda errors.

I have drove the car, with a difficult start, but then it worked fine,
on the highway with 130 - 160 km/h. When I got off the highway, after
couple of kilometers with 40 - 100 km/h, the ESP warning on bord
lighted up. I have stoped and I have seen that I had the new error:

Control Module Part Number:
Component and/or Version: 1.8L R4/5VT 0001
Software Coding: 05710
Work Shop Code: WSC 00000
1 Fault Found:
16487 - Mass Air Flow Sensor (G70): Signal too High
P0103 - 35-10 - - - Intermittent

Even though I have cleared the error in the next 100 km it appeard
again a couple of times everytime announced by the ESP on bord.

I stoped, cleared the error, didn't start the car for few days then I
made around 300 KM - normal rode and highway. I had dificulties to
start the car but then it worked almost like before I changed the
debitmeter and ... I got no more errors! The next day, after a
difficult start I drove around 10 km but again no errors.

What I have noticed and I believe it is important is that whenever I
have dificulties to start the car, in the "001" Measuring Blocks field
in VAG-COM I got at "HOS2 Control" a constant "25%" value. Anytime
else I got a constant variation from -7% to +10%.

Well, that's the story... If it not clear please indicate me what else
should I do and what other data may I offer you. Maybe based on your
experience you can help me clarify:

- 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?

 

florinman@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 under acceleration but 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.

 

florinman@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 under acceleration but 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.

 

florinman@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 under acceleration but 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.

 

florinman@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 under acceleration but 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.

 

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 under acceleration but 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 still drop though... and the sound is still scratching my
nerves.
So you are saying that is the "Waste Gate Actuator"... Is this the
term audi uses 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?

 

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 under acceleration but 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 still drop though... and the sound is still scratching my
nerves.
So you are saying that is the "Waste Gate Actuator"... Is this the
term audi uses 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?

 

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 under acceleration but 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 still drop though... and the sound is still scratching my
nerves.
So you are saying that is the "Waste Gate Actuator"... Is this the
term audi uses 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?

 

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 under acceleration but 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 still drop though... and the sound is still scratching my
nerves.
So you are saying that is the "Waste Gate Actuator"... Is this the
term audi uses 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?

 

florinman@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 under acceleration but 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 still drop though... and the sound is still scratching my
> nerves.
> So you are saying that is the "Waste Gate Actuator"... Is this the
> term audi uses 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.