Hi folks my fabia is july 2011 with 18500 on the clock but ive noticed over the last few months that the rear back box is starting to rust in several areas, it looks to me that the rust is coming from the inside. What do you reckon my chances are on having it renewed under warranty. cheers folks.  

possibly..... you may as well try!

If its not blowing then i don't think so

If its not blowing then i don't think so

Not so good. :think:

exhaust vapors are corrosive so its not unusual to find inside rust in the exhaust system. stainless pipes get around this issue

Nowt worse than rusty pipes.

Do you do lots of short trips?

Could it be the condensation thats causing it to corrode from the inside?

Ive been of work from may last year after an operation so haven't been using the car much so condensation could be the problem. Cheers. 

Nowt worse than rusty pipes.

I clean my pipes regularly and very enjoyable it is too!

Cant be helped then i guess. Other than doing the odd decent trip out to burn off the moisture.

Might be worth trying to claim though, its worth a go

Lots of short trips? An exhaust guy once told me he would often get old blokes come into his shop complaining that they've hardly used their car and yet the (non stainless) mufflers were rusting. The theory is that condensation gets in there, and lots of short trips to the bowls, bingo etc doesn't do anything to evaporating that water. 

Lots of short trips? An exhaust guy once told me he would often get old blokes come into his shop complaining that they've hardly used their car and yet the (non stainless) mufflers were rusting. The theory is that condensation gets in there, and lots of short trips to the bowls, bingo etc doesn't do anything to evaporating that water.

Believe me it's never a pleasant experience when you have to examine an old mans crusty brown back-box.........

Hi OCD, I wouldn't worry about external corrosion. I'm pretty sure the back box is double skinned like the rest of the system on yours. So it probably isn't rusting from the inside...yet! It's normal. It won't be covered under warranty. Most systems do ultimately corrode from the inside. The water vapour from the engine actually turns to sulphuric acid inside the exhaust and eats the system away from the inside if you don't use the car enough to evaporate the water. The back box is the last part of the system to get hot so make sure you do a good run often to keep it clear of water. This avoids the problem. 

Thanks folks.