Tero Patana

(Sorry for this being so long, but I'm trying to tell everything so you
can try to make the whole picture of the problem)

I have a Audi A6 1996 with 2.6L V6-engine, with hydraulic valve lifters.
The car has been driven for about 85k miles (<140k km)

One and a half week ago when I started the engine, there was loud clatter,
like when the valves don't work ok, but this one was _loud_, believe me.

The oil change was due in near future, so I booked time from local
repairshop for oil and filter change.

I don't know what oil's there have been before, but when I bought the car,
I applied Mobil 1 0W-40 synthetic oil. I've only changed the oils once,
before this week.

The repairman said that the valve lifters need to be changed, as the noise
was too loud for normal operation.

So the valve lifters were changed, as well as the oil and filter.

And the noise didn't go away. Under the valve lifter gasket, there was lot
of ... something (not dirt, but something), so we figured out to try
engine flush and new oil change, if the something had clogged oil
journals (the oil channels are called journals, aren't they?) from other
V-branch. Also, when the gasket was removed, and the engine started, no
oil came there, just few drips from somewhere. So it seemed that the clog
in some journal stopped the oil from entering the valve lifters.

The flush seemed to do the trick, but when I had driven for few miles, the
clatter returned. Next day, I drove the car back. At first, the clatter
was there, but when I arrived at the repair facility, the engine was
quiet.

They did the engine flush again, along with the oil and filter change.
This time I drove around for 20 minutes nice and slowly, and engine seemed
ok. Just when I entered a freeway, the clatter returned. When I headed
back to the repair, the noise went away. I drove a little with higher rpm
(~3000 rpm), and the clatter returned, and when I drove more carefully, it
went away. For some moment, the clatter didn't return even with higher
rpm, but then with one faster acceleration, the clatter returned ok.

So it seemed when the rpm's were raised more than average, the clatter
came, and when driven slowly, it went away.


So what could be the problem?


I have been given thousands of hints, but not sure which one to try first.

One is the something in the engine, which might clog the journals again
and again. Several flushs might do the job, or maybe some other methods?

Can the over-pressure valve at the oil pump be defekt, so that it
starts to leak always when the rpm's are raised, thus negating the oil
pressure raise when accelerating? I suppose the oil pumps themselves
usually don't break down with this mileage, as well as they usually tend
to work better with high rpm's. The oil pressure light never lits, but can
I trust it?

Something wrong with the oil filter, or the interface between the engine
and the filter?

The rotating rod (shaft? cam shaft?) which moves the valve lifters, is/are
ok. What else should be checked before the engine is totally torn apart?


Hopefully someone has some ideas, any good advice would be appreciated.

-Tero

dave

>From: Tero Patana tpatana@mail.student.oulu.fi
>Date: 4/27/04 5:46 AM Central Daylight Time
>Message-id: <Pine.GSO.4.58.0404271318360.16997@paju.oulu.fi>
>
>
>(Sorry for this being so long, but I'm trying to tell everything so you
>can try to make the whole picture of the problem)
>
>I have a Audi A6 1996 with 2.6L V6-engine, with hydraulic valve lifters.
>The car has been driven for about 85k miles (<140k km)
>
>One and a half week ago when I started the engine, there was loud clatter,
>like when the valves don't work ok, but this one was _loud_, believe me.
>
>The oil change was due in near future, so I booked time from local
>repairshop for oil and filter change.
>
>I don't know what oil's there have been before, but when I bought the car,
>I applied Mobil 1 0W-40 synthetic oil. I've only changed the oils once,
>before this week.
>
>The repairman said that the valve lifters need to be changed, as the noise
>was too loud for normal operation.
>
>So the valve lifters were changed, as well as the oil and filter.
>
>And the noise didn't go away. Under the valve lifter gasket, there was lot
>of ... something (not dirt, but something), so we figured out to try
>engine flush and new oil change, if the something had clogged oil
>journals (the oil channels are called journals, aren't they?) from other
>V-branch. Also, when the gasket was removed, and the engine started, no
>oil came there, just few drips from somewhere. So it seemed that the clog
>in some journal stopped the oil from entering the valve lifters.
>
>The flush seemed to do the trick, but when I had driven for few miles, the
>clatter returned. Next day, I drove the car back. At first, the clatter
>was there, but when I arrived at the repair facility, the engine was
>quiet.
>
>They did the engine flush again, along with the oil and filter change.
>This time I drove around for 20 minutes nice and slowly, and engine seemed
>ok. Just when I entered a freeway, the clatter returned. When I headed
>back to the repair, the noise went away. I drove a little with higher rpm
>(~3000 rpm), and the clatter returned, and when I drove more carefully, it
>went away. For some moment, the clatter didn't return even with higher
>rpm, but then with one faster acceleration, the clatter returned ok.
>
>So it seemed when the rpm's were raised more than average, the clatter
>came, and when driven slowly, it went away.
>
>
>So what could be the problem?
>
>
>I have been given thousands of hints, but not sure which one to try first.
>
>One is the something in the engine, which might clog the journals again
>and again. Several flushs might do the job, or maybe some other methods?
>
>Can the over-pressure valve at the oil pump be defekt, so that it
>starts to leak always when the rpm's are raised, thus negating the oil
>pressure raise when accelerating? I suppose the oil pumps themselves
>usually don't break down with this mileage, as well as they usually tend
>to work better with high rpm's. The oil pressure light never lits, but can
>I trust it?
>
>Something wrong with the oil filter, or the interface between the engine
>and the filter?



Theory time..........
sounds like debris is in the oil pan and at higher rpms, the oil pump sucks at
a greater volume and the debris clogs the oil pump strainer.
Then the oil pump pumps less oil to the lifters and that noise develops.

Testing time.......
See if my theory is correct by installing an oil pressure gauge and observing
readings while conducting the same high rpm tests.

Or drop the pan to check and possibly change the oil pump.

Are you using good oil filters?
which brand?


later,
dave
Reminder........
Before you criticize someone, you should walk a mile in their shoes. That way,
when you criticize them, you are a mile away from them, and you have their
shoes. Frieda Norris

Tero Patana

On Tue, 27 Apr 2004, dave wrote:
> >From: Tero Patana tpatana@mail.student.oulu.fi
> >Date: 4/27/04 5:46 AM Central Daylight Time
> >Message-id: <Pine.GSO.4.58.0404271318360.16997@paju.oulu.fi>
> >
> >
> Theory time..........
> sounds like debris is in the oil pan and at higher rpms, the oil pump sucks at
> a greater volume and the debris clogs the oil pump strainer.
> Then the oil pump pumps less oil to the lifters and that noise develops.
>

This is very possible, I just wish this could be proven fact, and also
given a good solution to get rid of the debris.

> Testing time.......
> See if my theory is correct by installing an oil pressure gauge and observing
> readings while conducting the same high rpm tests.
>

This is one of the next things to try (I wonder why the repairman didn't
test this at first??)

> Or drop the pan to check and possibly change the oil pump.
>

I was told that this engine needs quite much labour (=cost) to open the
engine. So far, the costs have been quite nice, and almost nothing has
been done, so I wouldn't want to spend any more money at guesses. I wish
there was some way to make certain what is the problem.

> Are you using good oil filters?
> which brand?
>

Don't know, since the repairman has acquired them. Should be ok, but this
was one of the questions which I intended asking him next time I'm
visiting him.

One of the thousand quesses, was that if the filter has too small flow
holes (or what you call them?), then the oil flow "chokes" when it needs
to flow more. One quess, but I don't believe too much in this one.


-Tero

JP Roberts

Ever replaced the Belt and Belt tensioner?? I suspect your problem lies
either here or in the oil pump.

"Tero Patana" <tpatana@mail.student.oulu.fi> escribió en el mensaje
news:Pine.GSO.4.58.0404271318360.16997@paju.oulu.f i...
>
> (Sorry for this being so long, but I'm trying to tell everything so you
> can try to make the whole picture of the problem)
>
> I have a Audi A6 1996 with 2.6L V6-engine, with hydraulic valve lifters.
> The car has been driven for about 85k miles (<140k km)
>
> One and a half week ago when I started the engine, there was loud clatter,
> like when the valves don't work ok, but this one was _loud_, believe me.
>
> The oil change was due in near future, so I booked time from local
> repairshop for oil and filter change.
>
> I don't know what oil's there have been before, but when I bought the car,
> I applied Mobil 1 0W-40 synthetic oil. I've only changed the oils once,
> before this week.
>
> The repairman said that the valve lifters need to be changed, as the noise
> was too loud for normal operation.
>
> So the valve lifters were changed, as well as the oil and filter.
>
> And the noise didn't go away. Under the valve lifter gasket, there was lot
> of ... something (not dirt, but something), so we figured out to try
> engine flush and new oil change, if the something had clogged oil
> journals (the oil channels are called journals, aren't they?) from other
> V-branch. Also, when the gasket was removed, and the engine started, no
> oil came there, just few drips from somewhere. So it seemed that the clog
> in some journal stopped the oil from entering the valve lifters.
>
> The flush seemed to do the trick, but when I had driven for few miles, the
> clatter returned. Next day, I drove the car back. At first, the clatter
> was there, but when I arrived at the repair facility, the engine was
> quiet.
>
> They did the engine flush again, along with the oil and filter change.
> This time I drove around for 20 minutes nice and slowly, and engine seemed
> ok. Just when I entered a freeway, the clatter returned. When I headed
> back to the repair, the noise went away. I drove a little with higher rpm
> (~3000 rpm), and the clatter returned, and when I drove more carefully, it
> went away. For some moment, the clatter didn't return even with higher
> rpm, but then with one faster acceleration, the clatter returned ok.
>
> So it seemed when the rpm's were raised more than average, the clatter
> came, and when driven slowly, it went away.
>
>
> So what could be the problem?
>
>
> I have been given thousands of hints, but not sure which one to try first.
>
> One is the something in the engine, which might clog the journals again
> and again. Several flushs might do the job, or maybe some other methods?
>
> Can the over-pressure valve at the oil pump be defekt, so that it
> starts to leak always when the rpm's are raised, thus negating the oil
> pressure raise when accelerating? I suppose the oil pumps themselves
> usually don't break down with this mileage, as well as they usually tend
> to work better with high rpm's. The oil pressure light never lits, but can
> I trust it?
>
> Something wrong with the oil filter, or the interface between the engine
> and the filter?
>
> The rotating rod (shaft? cam shaft?) which moves the valve lifters, is/are
> ok. What else should be checked before the engine is totally torn apart?
>
>
> Hopefully someone has some ideas, any good advice would be appreciated.
>
> -Tero

Tero Patana

On Tue, 27 Apr 2004, JP Roberts wrote:

> Ever replaced the Belt and Belt tensioner?? I suspect your problem lies
> either here or in the oil pump.
>

Not sure about the tensioner, but the belt is changed 10k miles ago (~16k
km).

Can it be the pump, if the other V-brach works (or at least seems to)
correctly?

Steve Sears

Tero,
Sounds like the "Orange Filter of Engine Death" to me - paper element cannot
handle the high oil flow and implodes - sucking chunks of paper into the oil
passageways in the engine. I've only heard of this with older 200/5000
turbo engines, but the filter that may have been the culprit was thrown out
with the oil/filter/lifter change, right? Unfortunately, the people who I
have heard this happen to have had to undertake a major motor rebuild to get
the fluff out of the system. When the engine was flushed, did you look to
see what came out in the flow?
Given that the engine is so new, and the onset of the noise so
instantaneous, it's a wonder why your repair guy didn't drop the pan - maybe
it's time to change the repair facility before they change anything else on
spec.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)

"Tero Patana" <tpatana@mail.student.oulu.fi> wrote in message
news:Pine.GSO.4.58.0404271446050.16997@paju.oulu.f i...
> On Tue, 27 Apr 2004, dave wrote:
> > >From: Tero Patana tpatana@mail.student.oulu.fi
> > >Date: 4/27/04 5:46 AM Central Daylight Time
> > >Message-id: <Pine.GSO.4.58.0404271318360.16997@paju.oulu.fi>
> > >
> > >
> > Theory time..........
> > sounds like debris is in the oil pan and at higher rpms, the oil pump
sucks at
> > a greater volume and the debris clogs the oil pump strainer.
> > Then the oil pump pumps less oil to the lifters and that noise develops.
> >
>
> This is very possible, I just wish this could be proven fact, and also
> given a good solution to get rid of the debris.
>
> > Testing time.......
> > See if my theory is correct by installing an oil pressure gauge and
observing
> > readings while conducting the same high rpm tests.
> >
>
> This is one of the next things to try (I wonder why the repairman didn't
> test this at first??)
>
> > Or drop the pan to check and possibly change the oil pump.
> >
>
> I was told that this engine needs quite much labour (=cost) to open the
> engine. So far, the costs have been quite nice, and almost nothing has
> been done, so I wouldn't want to spend any more money at guesses. I wish
> there was some way to make certain what is the problem.
>
> > Are you using good oil filters?
> > which brand?
> >
>
> Don't know, since the repairman has acquired them. Should be ok, but this
> was one of the questions which I intended asking him next time I'm
> visiting him.
>
> One of the thousand quesses, was that if the filter has too small flow
> holes (or what you call them?), then the oil flow "chokes" when it needs
> to flow more. One quess, but I don't believe too much in this one.
>
>
> -Tero

JP Roberts

I had some noise at tilt, and some detonation under load at around 1950
rpm - on my 1.8T, and it all disappeared when I had the belt, tensioner and
the V-branch pulleys replaced. Since your car has over 140 thousand km in
the counter, you should already have had those replaced quite some time ago,
so I'd suggest your doing this before any further attempts at replacing the
pump.

Also, since it seems to be the case that the noise occurs under engine
load - as you mentioned - this might indicate that there could possibly be a
bad belt tooth causing detonation because of excessive timing advance at
certain times when the bad belt tooth sent the wrong ignition timing.
Because it's a six cyl. power loss might not be so noticeable as it would on
a 4 cyl. engine.

My two cents,

JP Roberts


> Not sure about the tensioner, but the belt is changed 10k miles ago (~16k
> km).
>
> Can it be the pump, if the other V-brach works (or at least seems to)
> correctly?

dave

edited

>From: Tero Patana tpatana@mail.student.oulu.fi
>> Theory time..........
>> sounds like debris is in the oil pan and at higher rpms, the oil pump sucks
>at
>> a greater volume and the debris clogs the oil pump strainer.
>> Then the oil pump pumps less oil to the lifters and that noise develops.
>>
>
>This is very possible, I just wish this could be proven fact, and also
>given a good solution to get rid of the debris.
>

get some oil pressure readings at different rpms and/or while that lifter noise
is occuring

>> Testing time.......
>> See if my theory is correct by installing an oil pressure gauge and
>observing
>> readings while conducting the same high rpm tests.


later,
dave
Reminder........
Before you criticize someone, you should walk a mile in their shoes. That way,
when you criticize them, you are a mile away from them, and you have their
shoes. Frieda Norris

Tero Patana

On Tue, 27 Apr 2004, Steve Sears wrote:

> Tero,
> Sounds like the "Orange Filter of Engine Death" to me - paper element cannot
> handle the high oil flow and implodes - sucking chunks of paper into the oil
> passageways in the engine. I've only heard of this with older 200/5000
> turbo engines, but the filter that may have been the culprit was thrown out
> with the oil/filter/lifter change, right? Unfortunately, the people who I
> have heard this happen to have had to undertake a major motor rebuild to get
> the fluff out of the system. When the engine was flushed, did you look to
> see what came out in the flow?

I wasn't around when the engine was flushed, so didn't get to see the oil.
I guess that the filters aren't the cheapest around (nor the most
expensive), but I suppose I will ask the repairman about the filter. They
are experienced with Audis, so I assume they shouldn't have done a mistake
that stupid. I really hope this isn't the case, since rebuilding the
engine doesn't sound too cheap solution. In addition to stupid car tax
regulations here, there is some limits how costly repairs are reasonable
to do for cars that old.

> Given that the engine is so new, and the onset of the noise so
> instantaneous, it's a wonder why your repair guy didn't drop the pan - maybe
> it's time to change the repair facility before they change anything else on
> spec.

Around here, there's two choices. Either the local Audi dealer, which
costs like hell, or private repairs, which cost moderately cheaper, and in
fact, in many cases do better job than the dealer. This one seemed to be
better than average experienced with Audis, so I wish I could rely on
their expertise.


Thanks for the tips Steve.


-Tero

Tero Patana

On Tue, 27 Apr 2004, JP Roberts wrote:

> I had some noise at tilt, and some detonation under load at around 1950
> rpm - on my 1.8T, and it all disappeared when I had the belt, tensioner and
> the V-branch pulleys replaced. Since your car has over 140 thousand km in
> the counter, you should already have had those replaced quite some time ago,
> so I'd suggest your doing this before any further attempts at replacing the
> pump.
>
Hmm.. given my great knowledge about English, what you mean with V-branch
pulleys? When I was talking about V-branch before, I meant the other half
of my V-engine. I recall 1.8T is not V, but straight.

But if the belt is changed under 16 thousand km ago, I suppose it
shouldn't be problem yet?

> Also, since it seems to be the case that the noise occurs under engine
> load - as you mentioned - this might indicate that there could possibly be a
> bad belt tooth causing detonation because of excessive timing advance at
> certain times when the bad belt tooth sent the wrong ignition timing.
> Because it's a six cyl. power loss might not be so noticeable as it would on
> a 4 cyl. engine.
>

What indicates that it is not timing nor ignition problem, is that when
they removed the valve lifter gasket, no oil came there when the engine
was running.

So most probably the problem is somewhere in the oil flow chain, the pump,
the filter, the journals etc... or maybe not


Any comments or suggestions are appreciated, since the real cause is still
unknown. I just personally suspect the oil flow chain.

Thanks for comments,

-Tero