A/C strange behavior

Car is a 99' A6 2.8 Q with only 25K miles. The A/C, every now and then,
would blow warmer than expected cold air; one time going through a car wash
I put trans in "N" neutral and the air temp went totally warm as if A/C is
not running at all. In all these cases if I put the recirculation on the
temp returns to cold almost immediately.

I don't think this is a refrigerant issue but maybe an air gate or (less
probable) belt issue.

Any help here is welcome

In my '98 A6Q (wagon) I had a similar problem. Identical actually, except
that I never played with the recirculation button to see if that would have
any effect. My problem turned out to be a bad water temp sensor. The
computer would get a high reading from this bad sensor and think that the
engine was overheating and would cut out the A/C to give the engine a break.

I cannot recall now if the water temp guage indicated that the engine was
overheating. Maybe not, as I think that the 2.8 engine has more than one
water temp sensor.

I'd guess that this is not your problem as I do not see how the
recirculation button would cause the A/C to kick back in if it were. But, I
contribute it for whatever it might be worth.

Good Luck, Bob


"Tony" > wrote in message
...
> Car is a 99' A6 2.8 Q with only 25K miles. The A/C, every now and then,
> would blow warmer than expected cold air; one time going through a car
wash
> I put trans in "N" neutral and the air temp went totally warm as if A/C is
> not running at all. In all these cases if I put the recirculation on the
> temp returns to cold almost immediately.
>
> I don't think this is a refrigerant issue but maybe an air gate or (less
> probable) belt issue.
>
> Any help here is welcome
>
>
>
>