Exhaust Corrosion ?

WD Pro

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What material are our exhausts made out of and is exhaust corrosion a problem on the S550 (I have active exhaust if that makes a difference) ?

I am asking because our euro cars get a very thick (and inconsistent) coating of black underseal which quite honestly looks a right mess.

1641986868423.jpeg


It's particularly bad on the exhaust - In some places it has run, partially dripped and then dried. In others it has bubbled due to heat before it has cured, then cured with the bubbles set like mini craters.

As I want to fit the H pipe soon, I'm thinking of taking the opportunity whilst the exhaust is off to paint strip it back to its OE finish. IMHO it will look nicer that way then the 'can't be arsed just spray everything' coating that we currently get ...

Thanks for any replies :like:

WD :like:

 

bnightstar

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All the underside exhaust, driveshaft, differential are metal and a cheap metal at that which mean that they are prone to corrosion. You can look photos of Florida or CA cars that have everything rusted out on 2-3 years old Mustang. Which is why you always should keep your car dry and store it in a garage space where corrosion is no issue. Hope this helps.
 

Dana Pants

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The exhaust is low grade stainless steel and will likely last the life of the car.

The clamp bolts might rust out at some point, as I have seen on other cars, but overall the exhaust should be rather robust.
 

Rapid Red

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"You can look photos of Florida or CA cars that have everything rusted out on 2-3 years old Mustang, cars"

That's a pretty bold statement right there. I will ignore commenting on its truthfulness, usefulness, or accuracy, it speaks for itself.

Early on dealers undercoated cars as an upgrade for a new car.

I would not remove it, see a missed spot, clean the area. Most likely mineral spirits will do the trick. And reapply, the undercoat was a tar-like substance back in the day. Unknown to me these days.

It BTW also knocks down road noise. Every exhaust system will have some rust ......... the heat cycles and condensation generated are the cause.
 

ICU812

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"You can look photos of Florida or CA cars that have everything rusted out on 2-3 years old Mustang, cars"

That's a pretty bold statement right there. I will ignore commenting on its truthfulness, usefulness, or accuracy, it speaks for itself.
Well, depends on where in those states the car lives, near on the coast, salt water air does a number on metal , but outside those areas, or a flood, cars in those states don't rust in 2-3 years.
If it is true that the whole exhaust is s/s then great, I don't know. so?
But most exhaust systems rot from the inside out cat back as the cat, makes/converts gases to H2O and short drives that don't get hot enough to turn it into steam and out the pipe rot out faster than vehicles that go on longer drives .
It be nice if the whole exhaust is in fact s/s , then it is just a matter of keeping the hardware from rusting, and hanger welds. And the moving parts of the active valve
 


Rapid Red

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Well, depends on where in those states the car lives, near on the coast, salt water air does a number on metal , but outside those areas, or a flood, cars in those states don't rust in 2-3 years.
If it is true that the whole exhaust is s/s then great, I don't know. so?
But most exhaust systems rot from the inside out cat back as the cat, makes/converts gases to H2O and short drives that don't get hot enough to turn it into steam and out the pipe rot out faster than vehicles that go on longer drives .
It be nice if the whole exhaust is in fact s/s , then it is just a matter of keeping the hardware from rusting, and hanger welds. And the moving parts of the active valve

Living & growing up in Miami for 35+ years, I'm damn comfortable with the accuracy of my assessment.

Rock on ...
 

Gregs24

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All the underside exhaust, driveshaft, differential are metal and a cheap metal at that which mean that they are prone to corrosion. You can look photos of Florida or CA cars that have everything rusted out on 2-3 years old Mustang. Which is why you always should keep your car dry and store it in a garage space where corrosion is no issue. Hope this helps.
My car lives outside - is a daily driver and at 3 years old is still clean as a whistle underneath with no corrosion.
 

GregO

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What material are our exhausts made out of and is exhaust corrosion a problem on the S550 (I have active exhaust if that makes a difference) ?

I am asking because our euro cars get a very thick (and inconsistent) coating of black underseal which quite honestly looks a right mess.

1641986868423.jpeg


It's particularly bad on the exhaust - In some places it has run, partially dripped and then dried. In others it has bubbled due to heat before it has cured, then cured with the bubbles set like mini craters.

As I want to fit the H pipe soon, I'm thinking of taking the opportunity whilst the exhaust is off to paint strip it back to its OE finish. IMHO it will look nicer that way then the 'can't be arsed just spray everything' coating that we currently get ...

Thanks for any replies :like:

WD :like:
OEM Ford exhaust systems are 400 series stainless steel. Unlike 300 series stainless steel 400 has a higher iron content which is the reason the OEM systems develop an iron oxide surface. This is 100% normal, the service life of 400 series will outlast the vehicles service life. With a red Scotchbrite pad and some effort the oxide layer can be removed BUT it will return again over time.
Hope this helps.
 

bnightstar

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My car lives outside - is a daily driver and at 3 years old is still clean as a whistle underneath with no corrosion.
good for you but mine is a garage queen though sitting on a lot for 2 years before me and the diff is starting to rust mine has the Iron cover though so that might be normal/expected. And a friend of mine imported a car from the States from an action with rear damage fixed it and exhaust, diff cover and driveshaft are all orange so I think I know what I'm talking about based on what I have seen. There is a lot of orange photos on this forum as well from some cars. And my biggest scare for mine when I bought it after 2 years on the lot was hoping to not look like this as well lucky for me it's not the case. But now it's start developing some rust.
 

Basspro302

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good for you but mine is a garage queen though sitting on a lot for 2 years before me and the diff is starting to rust mine has the Iron cover though so that might be normal/expected. And a friend of mine imported a car from the States from an action with rear damage fixed it and exhaust, diff cover and driveshaft are all orange so I think I know what I'm talking about based on what I have seen. There is a lot of orange photos on this forum as well from some cars. And my biggest scare for mine when I bought it after 2 years on the lot was hoping to not look like this as well lucky for me it's not the case. But now it's start developing some rust.
The diff cover is aluminum.
 

bnightstar

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