Decision time

[urq]

With all the traffic on this I went back and read the initial post ... there
are a couple non-sequiturs I see.  You didn't say, but I would expect that
the car was running somewhat normally when you shut it down.  Given that, it
seems a bit odd to me that you would have significant damage to the
combustion chamber components.  I would have also expected that a '99 A4
would have some sort of dynamic oil pressure monitoring system like Audi
started using in the late '80s.  I've never done an experiment, but I would
expect that you were so low on oil that the sump was sucking air a
significant part of the time I'd expect you'd get some indication at idle.
Audi's rationale behind adding the dynamic system was to provide information
that there's a problem when the engine should be producing full pressure.
Those of us with the older cars where the dynamic system errantly reported a
problem know that the root cause was that the test was being done at too low
an RPM ... which tells me that the pressure limit must be set fairly high.  

Perhaps you are the person in the best position to evaluate this, but one
advantage of reworking your car is that it is a known quantity ... if you
know that the rest of the car is sound you have that information, which you
would not have in the replacement.  Even if the engine is now a boat anchor,
that doesn't cause any doubt about the functionality of the rest of the car.
Following that logic, should you decide to pay to bring the car back to life
I'd recommend doing a complete engine swap.  The risk that the bottom end of
the engine is damaged would cancel any reliability benefits you'd get from
having the "known quantity" of the rest of the car.  

Good luck to you as you make the decision.  I struggled similarly when I
still had the WX in the car ... and I tend to be minimalistic (read: cheap)
in what I do for repair, so it was good that a coolant leak in the head
gasket gave me certainty that the bottom end of the engine was unusable.
The total to swap the MC-2 in was quite similar to what you're being quoted
for your A4 ... and I must say that I'm glad I did it.  I know that the
engine is robust, which makes me less hesitant to use the car.  

Hope this helps somehow!

Steve B
San Jose, CA (USA)

-----Original Message-----

If your oil consumption (or leak rate) was 1 qt/1500 miles (which, as I
recall VAG would consider acceptable) then in 4500 miles, your sump would've
been essentially dry.

The problem with the high speed low pressure switch is by the time the pump
isn't sucking enough oil to generate enough pressure to support the
bearings, the time you have for shut down is probably like 1 second anyway,
so a warning (although it should have at least told you you were toast
anyway) wouldn't have helped much anyway.

LL - NY

On 1/9/09, Kent McLean <kentmclean at comcast.net> wrote:


As for the oil, I've been commuting 1400 mi/week. Let's say that
> over the holidays I missed checking it for 3 weeks (I had meant to
> change the oil at 130K; but I was too dang busy).
>
> Is 4500 miles enough to use 3 qts (which is what it was down)?
> Maybe.
>
> Should that have killed the engine without a least a low-oil
> pressure warning?
> Not in my book.
>
> I can't imagine what it would take to trigger the low oil pressure
> light.