the floor pans can sometimes be a little challenging. From
the inside you have to pull the carpeting and padding back
first, then the sound proofing material is exposed. The
material is bonded on to the floor pans and is not easily
removed. The only way to check for rust problems in this
area (if the car you're inspecting isn't yours!) is around
the outside near the edges. Around the base of the pedals
is a common area for problems, and just about every other
area where water collects. Inspecting from the underside
of the car can be tricky too. Unless the car has had some
work done to it in the past, it will have an undercoating
on the entire underside of the pan. This undercoating can
help protect against rust, but it can also help hide it.
problems in floor pans can be attributed to several causes.
Any rubber seal that keeps the elements out of the passenger
compartment can be suspect for a path for water to enter
the car. Since the floor pans are the lowest point, any
water will collect there. A leaky windshield gasket is probably
the most common cause, but water could also be entering
through the underside of the pedal assembly and the underside
of the floor pans themselves. Each of the four floor pans
has a large circular "drain plug" that can allow
water and moisture in from the bottom if not properly sealed.