rust protection

[xusword]

Hi:

I bought my car pre-owned. I didnt know about asking undercoating because I thought it was mandatory in Ontario. I discover one day that my muffler has quite a bit of rust on it and wonder should I be worried about that. I never checked underneath my car though. Does it mean other parts of the car could be rusting too? Would it be too late to do the undercoat now if it starts rusting already? What else can I do about this?

 

[JohnD]

mufflers (silencers) are disposable items which need to be replaced from time to time (unless you buy a stainless steel one). As they are hot they can't be treated with underseal or preservative paint.

The catalytic converter is likely to be made of stainless.

If you have a Japanese or European car manufactured in the last 10 years or so it is likely to be made of zinc-plated steel. Provided it is painted, and you have any scratches or chips painted over promptly, it will not rust in a normal vehicle lifetime.

If you ask the car manufacturer they should be willing to tell you if it is made of Zintec (TM) or similar.

I don't know what American cars are made of.

Generally speaking, painting over rust does not stop it spreading.

 

[djheath]

Mild steel exhausts(mufflers) rust full stop (period). Usually you get about 2 years worth of life out of them maybe more, maybe less. Eventually they will rust through - usually from the inside out! One of the products of combustion is water, which will help to rust the exhaust from the inside.

Unless you get a stainless exhaust (costly), it will still rust pretty much in a few years. Nothing much to worry about until the exhaust starts blowing through holes in the pipes, joins etc.