Audi Won't Fix A4 Engine Noise

[Stephen Kormilo]

Help!!!  I have posted about this in the past, but 'crunch' time has
arrived :-(

For nearly two years now, the 2.8 l, 30 valve V6 engine in my 1998.5 Audi
A4 with 41,000 km has been making a loud 'rattling' or 'knocking' sound for
a second or two when starting the engine 'cold'. I originally thought that
this was lifter noise, but the Audi mechanic at the local dealer indicated
that was not the case. First, Audi suggested changing the oil and filter.
Noise persisted. They then tried changing to Mobil 1 synthetic oil. Still
noisy. In October, 2000 they changed the cam chain tensioners. It appears
that there is a chain that connects the intake and exhaust cams on each
bank. Seemed OK for a very short time, but the noise returned. After having
the Regional Rep look and listen to my engine start (unfortunately, because
the temperature was quite high, he didn't hear the full 'glory' of the
noise), Audi again replaced the tensioners, with what I was informed were
'new & improved' versions in August of this year, but the noise still
persists. Now they say that there is nothing more that they can do and for
me to put up with the 'annoyance'.

My warranty has just expired and I am very concerned about the long-term
health of the engine as well as the value of my car should a prospective
buyer hear the noise. Since Audi refuses to do anything else, I have
obtained the application forms for the Canadian Motor Vehicle Arbitration
Plan (CAMVAP).  Before I complete the forms and submit supporting
documentation, I would like to know if any one could provide me with advice
as to how to make the strongest possible case to the arbitrator and what to
expect during the hearing.

I can send a WAV file of one or more of the cold start noise events to
anyone who is interested.

There is also what appears to be an engine vibration or 'roughness' at
about 1500 rpm and again at about 1900 rpm, which can be detected by slowly
increasing the engine revs in neutral while holding the steering wheel.
There is a distinct 'roughness' near each of these engine speeds. I mention
this because I have five recordings of the cold start noises and in each of
these, the noises occur at about 30ms intervals and persist for about 1s.
My calculations indicate that a 30ms interval corresponds to an engine
speed of 2000rpm, the approximate engine speed right after the engine
'catches' and where one of the vibration events occurs. I feel that one
noise event every crank revolution and engine vibrations are signs of major
internal mechanical problems. The noise events last a little longer, up to
2 or 3s as the temperatures drop, although I don't have any recordings of
these.

To top it off, the engine oil consumption of about 1 litre every 3,000km is
at what I have been told is the high end of acceptable consumption for an
engine of this type, again pointing to internal engine problems.

Any and all advice and/or assistance welcomed.
Stephen Kormilo                            Silver '98.5 Audi A4 2.8QM
Instructor, Electronics Technology
Red River College
Winnipeg, MB
CANADA

email: skormilo at rrc.mb.ca
OR
           stephen at kormilo.ca