generic A4 questions

[Grant Lenahan]

Absolutely warm up is a major PITA - but that's the price of a turbo. 
We're enthusiasts, right?

By "careful warm up" I mean the following:

ANY car should be driven lightly (modest rpms and modest power/throttle 
opening) until it is fully warmed up. In reality, this mean *really* 
easy when seriously cold, and more energetically along the progression 
until its warm.  There's far too much to go into, but when cold the oil 
is not flowing well, and, more importantly, the parts do not fit 
together to design spec until warm.  Stuff expands with heat and cant 
fit properly both cold and warm - simple fact.  Amazing, overlooked, 
argued about, but true.

With turbos its just more important since anything spinning at 10k-100k 
rpms puts an incredible strain on the ability of a thin film of oil to 
resist shear. Shear = lubrication failure = metal to metal = impending 
death, and $2k-$5k out of your pocket.

The flip side is "cool down".  Turbos glow red in the summer night 
after spirited driving. I've seen them.  That's in the range of 700-800 
deg for red visibility in dark conditions.  That, in turn, is hot 
enough to break down any oil.  The problem is that hot oil runs through 
the red-hot turbos and, when you shut the car down, stops flowing. It 
sits there and cooks.  It thickens and coagulates, or, under extreme 
conditions, forms tiny abrasive carbon deposits called "coke". Yea, the 
stuff they use to fire steel mills - nearly pure carbon. very hard, and 
sand-papers itself through pussy soft steel like butter.  If it just 
thickens, it restricts flow through the oil return and slowly gives 
your car a heart attack - lack of oil flow to the critical turbo. I 
guess that's actually more of a stroke, to make an accurate, although 
imprecise, analogy.

So, warm-up and cool down, and that oil change stuff is a PITA for Joe 
Public.  But those on this list are not joe public, I assume.  If you 
use minimal common sense and even follow the owner's manual (plus cut 
the oil change intervals in half to account for the fact that EVERY car 
sees "severe service", as the owners manual states, but weasel-words, 
in accordance with API wording) - this motor is pretty damn tough.

Nothing against the v6.  I've had 'em all, and worked on them all.  But 
There are real advantages to the I4 turbo, and its rally not much 
trouble to change the oil with mobil1 every 5k miles.

If absolute convenience is one's priority - then a NA (non turbo) motor 
is clearly the way to go.  I would also suggest those folks get 
something like a Chevy Malibu - no, rally!. As C&D recently wrote: "GM 
cars run bad longer than most cars run at all". If that's what you 
want, Malibus are cheap, roomy, tough, and totally un-loveable.

I'm commenting on how to get a better performing, better balanced 
(weight), cheaper to run and fix, more easily pumped up car for less 
money.  You don't have to want that, of course.  Just understand the 
trade-off.

Grant


On Feb 4, 2007, at 4:50 PM, Alex Cagann wrote:

> Grant, I am no tech, and if you are correct...I still have to offer up 
> this
> opinion: Taken as a whole, the general public is lazy, and don't want 
> a car
> they have to take 'special' care of to keep running. What do you mean 
> by
> 'careful warm up'. Sounds to me like an inconvenience...and, at least 
> in the
> US, we don't like any of those! :-)
>
> Alex
>
>> -----Original Message-----
>> From: Grant Lenahan [mailto:glenahan at vfemail.net]
>> Sent: Sunday, February 04, 2007 2:44 PM
>> To: Alex Cagann
>> Cc: 'Tom Love'; 'Q-list'
>> Subject: Re: generic A4 questions
>>
>> Nah, Its lack of maintenance.  Those motors require
>> synthetic, regular (5k or less) changes, and careful warm up.
>> The vast majority of owners do none of the 3.  Sludge can be
>> a problem if oil remains too long - note that AOA issued a
>> TSB and lowered the change interval. Turbos and the oil
>> return lines can fail if synthetic is not used (the oil cokes
>> and coagulates on the inside of the return line - same as
>> S4s).  These risks are well known - although Audi as usual
>> tried to ignore them and did not warn customers (long oil
>> change intervals, blah, blah). The head gasket issue I'm
>> unaware of. The lower main bearing is quite rare, but would
>> be tied to sludge buildup, whcih is well documented - even with TSBs.
>>
>> This is maybe VW's most proven motor - dating in part back to
>> the 1980s VW 16V.
>>
>> Don't believe that these issues were not 100% foreseen.  I
>> called these problems ages back, as did many others.  In
>> fact, its amazing that people dont anticipate these issues in
>> any turbocharged motor. Temps are high at the impeller, and
>> this has a ripple effect if you dont keep fresh oil with a
>> high flash point.
>>
>> Take care of it and it will take care of you.  And reduce
>> polar moment of inertia, along the way.  And deliver better
>> fuel economy.  And take added boost happily.
>>
>> Grant
>> On Feb 4, 2007, at 3:35 PM, Alex Cagann wrote:
>>
>>> I agree completely here.  The V6 is very smooth, IMO, much
>> more than
>>> the 1.8t. Also, and I brought up a topic on this late last
>> year, but
>>> the
>>> 1.8
>>> engine is showing problems arise. Most didn't agree with me
>> at all and
>>> said they were all due to user errors (no preventative maintenance)
>>> but I am going to have to disagree here. While some may be
>> the case, I
>>> am seeing and hearing the stories build up. I visited my
>> tech friend
>>> the other day, and he had 3 of them just come in. I had
>> another talk
>>> about these engines with him, asked him about it. He said among his
>>> peers, they are seeing these come in like crazy. I asked him if he
>>> thinks it is due to lack of proper maintenance...he said no, not in
>>> most cases. He told me they are blowing head gaskets quite
>> a bit, and
>>> he is seeing a lot of them with lower crank bearing
>> failure. There has
>>> to be something here, or these tech's wouldn't be seeing so many of
>>> them.
>>>
>>> Alex
>>>
>>>> -----Original Message-----
>>>> From: Tom Love [mailto:theloves at localaccess.com]
>>>> Sent: Sunday, February 04, 2007 1:24 PM
>>>> To: Grant Lenahan; Alex Cagann
>>>> Cc: 'Q-list'; kf21857 at comcast.net
>>>> Subject: Re: generic A4 questions
>>>>
>>>> The refresh was 99.5 and still had a throttle cable.
>>>> IMO the NA 2.8 30v is about as fast as the stock 1.8T  (drive them
>>>> both) but smoother and far more trouble free. You can get
>> a lot more
>>>> power out of the 1.8T with mods but again, you are open for more
>>>> problems down the road.
>>>> If I bought another Avant I would be looking at a B6 if
>> not another
>>>> 99.5 B5 and still stick with the V6 and sport suspension.
>> My 2 cents
>>>
>>>
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>>
>
>