Porsche 911 Carrera Manual page 178

Warning!
Danger of fire and serious personal injuries.
f Do not apply additional undercoating or rust-
proofing on or near the exhaust manifold, ex-
haust pipes, catalytic converters or heat
shields. During driving the substance used for
undercoating could overheat and ignite.
f Before applying fresh underseal, carefully re-
move any deposits or dirt and grease. Once it
has dried, the new undercoating compound
forms a tough protective coating which pro-
vides efficient rust-proofing of the floor panels
and components.
f Always apply a fresh coating of suitable pre-
servative to unprotected areas after cleaning
the underside of the body, the transmission,
the engine or carrying out repairs to under-
body, engine or transmission components.
Effective rust-proofing is particularly important
during the cold weather season. If your car is driv-
en frequently in areas where salt has been spread
on the roads, the whole engine compartment
should be cleaned thoroughly after the winter to
prevent salt from causing any lasting damage. A
full under-body wash should also be performed at
the same time.
178
Maintenance, Car Care
Light alloy wheels
f Please observe the chapter "WASHING" on
Page 175.
Pitting may occur if metallic particles which cause
contact corrosion (e.g. brass or copper in brake
dust) are allowed to remain on the aluminum for
too long.
f If possible, wash the wheels with a sponge or
wash brush about every two weeks. In areas
where salt is spread on winter roads or there is
a lot of airborne industrial dust, it is best to
clean the wheels weekly.
The Porsche Light Alloy Wheel Cleaner
(ph-value 9.5) can be used for this pur-
pose.
If the ph-value of the detergent is incor-
rect, the protective coating on the wheels
will be destroyed.
Polishes which dissolve oxides, such as those
frequently used for other metals, or abrasive
tools or agents are unsuitable because they
break down the oxide film of the protective
coating and will cause discoloration of the
wheel.
f Every three months, after cleaning, coat the
wheels with a car wax or non-corrosive grease
(vaseline).
Using a clean cloth thoroughly rub the grease
into the surface.
Door, roof, lid and window seals
f Wash dirt (e.g. abrasion, dust, road salts) from
all seals regularly using warm soapy water. Do
not use any chemical cleaning agents or sol-
vents.
When there is a frost hazard, the outer door seals
and the front and rear lid seals can be protected
against freezing into place by a suitable care prod-
uct.
In order to prevent damage to the anti-
friction coating, the inner door seals must
not be treated with care products.