Hot times under the hood

[DeWitt Harrison <de@aztek-eng.com>]

I was sniffing around under the hood recently while the engine was still
warm and the cooling fan was running. I was interested in the throttle
idle/wot switch, but I noticed the fan was moving _cold_ air. I felt the
radiator: stone cold. Felt the head: very warm. I pulled a lead from the
after-run temperature switch and the fan stopped. Preliminary conclusion:
bad secondary cooling pump. I pulled the pump's electrical connector and
water dripped out. I measured the resistance of the pump motor and it
was infinite. She were a goner.

So far, so good. I bought a replacement pump and set about to install it
as soon as I returned home from work yesterday evening. Popped the
hood so things would cool down faster and, just to save a little time, I
started to ease the old pump out of it's rubber mounts. Nice and slow.
It was almost clear when the inlet tube of the pump simply snapped off
as though it was made of pasta. Hot water everywhere instantaneously.
I undertook evasive maneuvers, i.e. disorderly retreat, but still got scalded
a bit. What a damned idiot!

I knew better than to mess with a hot cooling system, but, no, I just had
to insist upon being stupid. If old age does not always bring wisdom, it
at least brings more scars. (The parts clerk at the dealership had even
joked about the great frequency with which the in-house service technicians
come up to the parts counter shame-faced with some pathetic tale about
having only just barely bumped the pump hose.)

On the positive side, I managed to stage this little drama in my own
driveway and not on the side of the road somewhere. As if you weren't
already sufficiently paranoid about 50 other seeds of impending doom
in your 10 year old Audi, I hereby add a cautionary note to the many
you've already read here regarding this little beauty: The pump ports
become _extremely_ brittle with age and will break easily and unexpectedly.
If your afterrun cooling pump is more than 100K miles old, I dare you to
tug on it's hoses. If you take me up on this, please let the engine cool down
first and arrange alternate transport ahead of time.

DeWitt Harrison    de@aztek-eng.com
Boulder, CO
88 5kcstq