BMW serie 3 sedan 2001 Manual Do Utilizador

Página de 211
147
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Index
Data
Technology
Repairs
Car care
Controls
Overview
Caring for your vehicle
Exterior finish 
To provide effective corrosion protec-
tion, multilayer paintwork is applied at 
the factory. Cataphoretic immersion 
priming techniques are supplemented 
using special body-cavity protectants, 
with the application of specially-devel-
oped and extensively tested materials.
A layer of flexible PVC is first applied 
to the undercarriage. Following this, a 
comprehensive undercoating treat-
ment with a wax-based protectant is 
applied. Regular maintenance makes 
an important contribution to maintaining 
the safety and value of your vehicle.
Increasing awareness of the effects 
of harmful environmental factors on 
vehicle finishes have urged paint and 
vehicle manufacturers to initiate 
ongoing programs designed to further 
improve the durability of their finishes. 
Despite this, environmental factors that 
occur locally or regionally can have 
negative effects on the finish of your 
vehicle. These should guide you in 
determining the frequency and extent 
of your efforts to maintain the vehicle 
finish.
Depending upon material and type 
of impact (perforation of paint layer), 
physical stresses from sand, road salt, 
gravel, etc., can cause corrosion to 
start extending beneath the finish, 
starting at the point of impact.
Road dirt, tar spots, dead insects, 
animal droppings (strong alkali effect) 
and tree excretions (resins and pollen) 
all contain substances capable of caus-
ing damage when allowed to remain on 
the finish of your vehicle for any period 
of time. This includes spots, etching, 
flaking, and separations in the top coat.
In industrial areas, deposits of flue dust, 
lime, oily soot, precipitation containing 
sulfur-dioxide (acid rain) and other 
environmental pollutants will damage 
the vehicle's finish unless adequate 
care is provided – even though this is 
generally limited to the outside 
horizontal surfaces.
In coastal regions, high levels of 
atmospheric salt and humidity promote 
corrosion.
In tropical zones, temperatures of over 
105 7 (40 6) in the shade prevail, in 
addition to heavy ultraviolet radiation 
and high humidity. Under those condi-
tions, light paints can reach tempera-
tures up to 175 7 (80 6) and dark 
paints up to 250 7 (120 6).
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