Curious 5000 Engine Problem

[dplain@disknet.com]

To 

	I have a customer with a curious intermittent problem.  He has a 87
5000s with about 150k that runs fine most of the time.  On some days if
he drives the car for about 1/2 to 1 hour it will sputter and die.  If
he reacts quickly enough holding the accelerator to the floor the car
will keep running (just barely).  If it quits, however, it will not
restart until it has sat for some time to cool off.  The weather has no
effect on its behaviour it will act-up without warning any time
anywhere.  When it dies it does not smoke, no warning lights, no odd
noises, nothing, before it quits.

	Naturally when he brings the car to me it works just fine.  Now I have
checked all of the obvious and not-so obvious things (fuel pump, fuel
quality, sensors, connectors, ignition, exhaust restrictions, etc.,
etc.).     

	Then he came to me today with what he thought was the answer: The car
only acted-up when it was one quart low on oil.  His fiance was driving
the car the other day when it quit.  She pulled off the road and checked
the oil -- one quart low.  She added a quart of oil started the car and
it ran fine all day.  I haven't tested his hypothesis but I have never
heard of such a thing.  

	Audi didn't put some kind of hidden low-oil shut down on their cars did
they?  Has anyone on the list heard of such a problem?  Any assistance
would be greatly appreciated.  Thanks, Dave.