CEL and code for 98 A4 2.8 Tip

My son's 2.8 tip has been displaying a CEL and occasionally flashing. I told him
tonight that flashing CEL means shut it off and correct immediately.

He says that when it flashes it usually goes away quickly and is fine for a day
or more the repeats.

Tonight we were at a friends place who has a VAG system and we pulled the codes.
It was outside in the dark and cold so we didn't get organized enough to write
them down but as I remember it the codes were referring to 'misfire on cylinders
4, 5, and 6 (all on drivers side bank).

The engine runs fine and doesn't seem to be going to limp mode.

The timing belt was done with all associated things last spring. The 'optional
Audi external oiling system' of the 30 valves was corrected this week but the
CEL issue was happening before and continues.

Plugs were recently replaced.

Plug wires are suspect.

He is getting some noise from his cam chains. The CEL seems to be more common
when idling so I was thinking that the knock sensor (this engine has one doesn't
it?) could be mistaking the chain noise for pre-ignition.

Any guesses?

TonyJ
My ride: 98.5 1.8TQM APR (faster than son's 2.8 tip)

Correction: I had misunderstood my son (That never happens to anyone else does
it?) about when the CEL started. Evidently it had only been displayed a few
times before having the work done.

He also said today that it seems to occur when idling or when accelerating but
goes away at a constant speed.

Tony wrote:
> My son's 2.8 tip has been displaying a CEL and occasionally flashing. I
> told him tonight that flashing CEL means shut it off and correct
> immediately.
>
> He says that when it flashes it usually goes away quickly and is fine
> for a day or more the repeats.
>
> Tonight we were at a friends place who has a VAG system and we pulled
> the codes. It was outside in the dark and cold so we didn't get
> organized enough to write them down but as I remember it the codes were
> referring to 'misfire on cylinders 4, 5, and 6 (all on drivers side bank).
>
> The engine runs fine and doesn't seem to be going to limp mode.
>
> The timing belt was done with all associated things last spring. The
> 'optional Audi external oiling system' of the 30 valves was corrected
> this week but the CEL issue was happening before and continues.
>
> Plugs were recently replaced.
>
> Plug wires are suspect.
>
> He is getting some noise from his cam chains. The CEL seems to be more
> common when idling so I was thinking that the knock sensor (this engine
> has one doesn't it?) could be mistaking the chain noise for pre-ignition.
>
> Any guesses?
>
> TonyJ
> My ride: 98.5 1.8TQM APR (faster than son's 2.8 tip)

Coils?

Tony
96 S6

"Tony" > wrote in message
...
> Correction: I had misunderstood my son (That never happens to anyone else
> does it?) about when the CEL started. Evidently it had only been displayed
> a few times before having the work done.
>
> He also said today that it seems to occur when idling or when accelerating
> but goes away at a constant speed.
>
> Tony wrote:
>> My son's 2.8 tip has been displaying a CEL and occasionally flashing. I
>> told him tonight that flashing CEL means shut it off and correct
>> immediately.
>>
>> He says that when it flashes it usually goes away quickly and is fine for
>> a day or more the repeats.
>>
>> Tonight we were at a friends place who has a VAG system and we pulled the
>> codes. It was outside in the dark and cold so we didn't get organized
>> enough to write them down but as I remember it the codes were referring
>> to 'misfire on cylinders 4, 5, and 6 (all on drivers side bank).
>>
>> The engine runs fine and doesn't seem to be going to limp mode.
>>
>> The timing belt was done with all associated things last spring. The
>> 'optional Audi external oiling system' of the 30 valves was corrected
>> this week but the CEL issue was happening before and continues.
>>
>> Plugs were recently replaced.
>>
>> Plug wires are suspect.
>>
>> He is getting some noise from his cam chains. The CEL seems to be more
>> common when idling so I was thinking that the knock sensor (this engine
>> has one doesn't it?) could be mistaking the chain noise for pre-ignition.
>>
>> Any guesses?
>>
>> TonyJ
>> My ride: 98.5 1.8TQM APR (faster than son's 2.8 tip)

Yes, we are a bit suspicious of that and probably should test them further.

One theory we are thinking about is the possibility of carbon buildup in the
drivers side bank causing pre-ignition. We 'think' this is possible because the
friend, who has worked on many audis and did the oil leak fixes for us, says
that that bank looked like the timing belt had been installed one tooth off. My
son and I did the T belt last spring and were not entirely confident that this
had not happened. If it had it seems that there could have been carbon build-up.
During the last months the car has thrown an occasional CEL which could be due
to mis-timing one one bank. The ECU may have attempted to accommodate this as
best it could.

Following the re-timing that was done the other day the ECU may now be a bit
confused at the change.

We are thinking about running some SeaFoam in a tank of gas and resetting the
ECU bey disconnecting the battery for a while after being sure that we have the
radio code following reconnection of the battery.

TonyJ

Tony Curran wrote:
> Coils?
>
> Tony
> 96 S6
>
> "Tony" > wrote in message
> ...
>
>>Correction: I had misunderstood my son (That never happens to anyone else
>>does it?) about when the CEL started. Evidently it had only been displayed
>>a few times before having the work done.
>>
>>He also said today that it seems to occur when idling or when accelerating
>>but goes away at a constant speed.
>>
>>Tony wrote:
>>
>>>My son's 2.8 tip has been displaying a CEL and occasionally flashing. I
>>>told him tonight that flashing CEL means shut it off and correct
>>>immediately.
>>>
>>>He says that when it flashes it usually goes away quickly and is fine for
>>>a day or more the repeats.
>>>
>>>Tonight we were at a friends place who has a VAG system and we pulled the
>>>codes. It was outside in the dark and cold so we didn't get organized
>>>enough to write them down but as I remember it the codes were referring
>>>to 'misfire on cylinders 4, 5, and 6 (all on drivers side bank).
>>>
>>>The engine runs fine and doesn't seem to be going to limp mode.
>>>
>>>The timing belt was done with all associated things last spring. The
>>>'optional Audi external oiling system' of the 30 valves was corrected
>>>this week but the CEL issue was happening before and continues.
>>>
>>>Plugs were recently replaced.
>>>
>>>Plug wires are suspect.
>>>
>>>He is getting some noise from his cam chains. The CEL seems to be more
>>>common when idling so I was thinking that the knock sensor (this engine
>>>has one doesn't it?) could be mistaking the chain noise for pre-ignition.
>>>
>>>Any guesses?
>>>
>>>TonyJ
>>>My ride: 98.5 1.8TQM APR (faster than son's 2.8 tip)
>
>
>