A6 misfire

I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
4. I put in some fuel injector cleaner and replaced the plugs and Cyl
#3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
still misfires. This is a very strange misfire. It misfires at idle,
off idle and under load but seems to go away at 2000 rpm with no load
and 2800 with load. This all started on the same day. Could it be fuel
injectors?

In article .com>,
Jims Audi > wrote:

> I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
> 4. I put in some fuel injector cleaner and replaced the plugs and Cyl
> #3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
> still misfires. This is a very strange misfire. It misfires at idle,
> off idle and under load but seems to go away at 2000 rpm with no load
> and 2800 with load. This all started on the same day. Could it be fuel
> injectors?

Is the compression OK? There's a scary chance that the head gasket blew
out between the two cylinders.

On Sun, 16 Sep 2007 13:47:45 -0700, Kevin McMurtrie >
wrote:

>In article .com>,
> Jims Audi > wrote:
>
>> I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
>> 4. I put in some fuel injector cleaner and replaced the plugs and Cyl
>> #3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
>> still misfires. This is a very strange misfire. It misfires at idle,
>> off idle and under load but seems to go away at 2000 rpm with no load
>> and 2800 with load. This all started on the same day. Could it be fuel
>> injectors?
>
>Is the compression OK? There's a scary chance that the head gasket blew
>out between the two cylinders.

ok, I'l confess to not knowing this for certain, but given the 2.7t is a V6,
does Audi number the banks 1-3 and 4-6, or do they stagger (odds on one side,
evens on the other)?

/daytripper
'00 s4 6spd

Standing in front of the car facing the radiator:



passenger side drivers side

3 6

2 5

1 4

/ Radiator /






















"daytripper" > wrote in message
...
> On Sun, 16 Sep 2007 13:47:45 -0700, Kevin McMurtrie
> >
> wrote:
>
>>In article .com>,
>> Jims Audi > wrote:
>>
>>> I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
>>> 4. I put in some fuel injector cleaner and replaced the plugs and Cyl
>>> #3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
>>> still misfires. This is a very strange misfire. It misfires at idle,
>>> off idle and under load but seems to go away at 2000 rpm with no load
>>> and 2800 with load. This all started on the same day. Could it be fuel
>>> injectors?
>>
>>Is the compression OK? There's a scary chance that the head gasket blew
>>out between the two cylinders.
>
> ok, I'l confess to not knowing this for certain, but given the 2.7t is a
> V6,
> does Audi number the banks 1-3 and 4-6, or do they stagger (odds on one
> side,
> evens on the other)?
>
> /daytripper
> '00 s4 6spd

On Sep 16, 8:57 am, Jims Audi > wrote:
> I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
> 4. I put in some fuel injector cleaner and replaced the plugs and Cyl
> #3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
> still misfires. This is a very strange misfire. It misfires at idle,
> off idle and under load but seems to go away at 2000 rpm with no load
> and 2800 with load. This all started on the same day. Could it be fuel
> injectors?

How do you know you have a misfire? You need to get the codes pulled.
Go to Autozone, they can do it for free. Then you can find out via
Google exactly what the issue is.

Dan D
'04 A4 1.8Tq MT-6
Central NJ USA

On Mon, 17 Sep 2007 15:41:42 GMT, "paul" > wrote:

>Standing in front of the car facing the radiator:
>
>passenger side drivers side
>
>3 6
>
>2 5
>
>1 4
>
> / Radiator /

Excellent.

And that would, as I suspected, rule out a siamesed head gasket on a 2.7t
between cylinders 3 and 4...

/daytripper
'00 s4 6spd

On Sep 16, 4:47 pm, Kevin McMurtrie > wrote:
> In article .com>,
> Jims Audi > wrote:
>
> > I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
> > 4. I put in some fuel injector cleaner and replaced the plugs and Cyl
> > #3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
> > still misfires. This is a very strange misfire. It misfires at idle,
> > off idle and under load but seems to go away at 2000 rpm with no load
> > and 2800 with load. This all started on the same day. Could it be fuel
> > injectors?
>
> Is the compression OK? There's a scary chance that the head gasket blew
> out between the two cylinders.

Compression is fine

On Sep 17, 2:06 pm, Dano58 > wrote:
> On Sep 16, 8:57 am, Jims Audi > wrote:
>
> > I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
> > 4. I put in some fuel injector cleaner and replaced the plugs and Cyl
> > #3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
> > still misfires. This is a very strange misfire. It misfires at idle,
> > off idle and under load but seems to go away at 2000 rpm with no load
> > and 2800 with load. This all started on the same day. Could it be fuel
> > injectors?
>
> How do you know you have a misfire? You need to get the codes pulled.
> Go to Autozone, they can do it for free. Then you can find out via
> Google exactly what the issue is.
>
> Dan D
> '04 A4 1.8Tq MT-6
> Central NJ USA

My neighbor has an ODB2 code reader. It says misfire on cylinder #4. I
can't get more specific without a VAG reader.

"Kevin McMurtrie" > wrote in message
...
> In article .com>,
> Jims Audi > wrote:
>
>> I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
>> 4. I put in some fuel injector cleaner and replaced the plugs and Cyl
>> #3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
>> still misfires. This is a very strange misfire. It misfires at idle,
>> off idle and under load but seems to go away at 2000 rpm with no load
>> and 2800 with load. This all started on the same day. Could it be fuel
>> injectors?
>
> Is the compression OK? There's a scary chance that the head gasket blew
> out between the two cylinders.

disconnect the battery and let the ecu set back to
default..............reconnect and run.

does it do it now.

"Sue Ridge" > wrote in message
...
>
> "Kevin McMurtrie" > wrote in message
> ...
> > In article .com>,
> > Jims Audi > wrote:
> >
> >> I have a misfire on my Audi A6 2.7t Quattro. It started on Cyl #3 and
> >> 4. I put in some fuel injector cleaner and replaced the plugs and Cyl
> >> #3 misfire went away. I replaced the coils on Cyl #3 and #4 but it
> >> still misfires. This is a very strange misfire. It misfires at idle,
> >> off idle and under load but seems to go away at 2000 rpm with no load
> >> and 2800 with load. This all started on the same day. Could it be fuel
> >> injectors?
> >
> > Is the compression OK? There's a scary chance that the head gasket blew
> > out between the two cylinders.
>
> disconnect the battery and let the ecu set back to
> default..............reconnect and run.
>
> does it do it now.
>
>
>

Disconecting the battery may cause the ECU to loose its memory on the
throttle body alignment settings, not a good idea unless you can re
calibrate it ;-)

Steve.