Interesting comment. However, cars are made to accomodate whatever they
encounter and car washes wouldn't be around for long if they regularly
did damage to the cars they wash. Do you (or anyone else here) have
first-hand knowledge of a car's systems being damaged by a car wash?
(Apart from removing loose bits of trim.)

Dan

(This account is not used for email.)

The underside of the car is sprayed just driving on a wet road.

When did it become common knowledge not to hose off the
engine?  I have for years and regularly do use a pressure
washer to keep the engine compartment and undercarriage
clean.  It makes it a lot easier to maintain and see
problems like oil leaks when they are small and easily
managed not to mention reducing the fire hazard created by
heavy accumulations of oil and debris.  In addition to being
easier to maintain, it is much more asthetically pleasing.
Any components that cannot withstand exposure to the
everyday elements to which they are exposed should not be
there in the first place.  If they are defective to the
point that a wash job disables them, they are already failed
or unreliable and, unsuitable for continued use.  The
failure to keep the components clean in a highly corrosive
operating environment is much more destructive than a good
cleaning.  It would probably be helpful in a corrosive
environment to spray the components with some sort of
corrosion inhibitor after cleaning and drying to retard the
effects of the road salts.  Leaving the road salts in place
is a guaranteed way to lead to damage.

Lugnut

Minicomputers don't fit in most cars. A small mini might fit in a wagon or
SUV, but you'd want at least a pickup truck to carry a reasonable sized
one.

Also, if it's common knowledge, why bother telling rec.autos.tech?

Ivan

Newsflash:  cars are designed to survive being driven in the rain.  Think
for once in your pathetic life.

Another newsflash:  the ECU is sealed and typically mounted in the passenger
compartment.

I put my vehicles up on the hoist and spray them down with a powerwasher
every few weeks in the winter months here in Michigan. The vehicles are
a '91 Lumina, '99 Chevy P/U and a 2003 Trailblazer. I have had no
problems with electronics failures and in the case of the Lumina it is
about the most mint undercarrige I have ever seen on a 16 year old rust
belt car, very little corrosion.

I firmly belive this contribues greatly to the longevity of a vehicle
that is subjected to road salt. The connectors used in the wiring of a
automobile are watertight and in the case of plugwires and such if they
are affected by moisture then they need to be replaced!

The manager at the NAPA store  says not to spray engine with hose. He's
a senior manager been around for years. Clean it with a rag and brake
parts cleaner only where needed.  Unlike water it evaporates fast.  He
should know because he's the one who sells you the computerized parts
when they short out.

The auto repair parts people love selling more parts to the lets hose
off everything boys.  Does your owners manual call for blasting the
motor with a garden hose?

Water splash from road is different than a high pressure blast from a
undercarriage wash. One has over 2000 psi the other doesn't.  One comes
from the side angle the other is blasting straight up to the bottom of
the hood.  For those of you who are still cant understand try this.
Splash a glass of water in you face.  Then use garden hose with blaster
nozzle and spray your closed eyes.  Maybe then you will understand
something.