Rust on Exhaust Flanges

[Kelvin]

I have a brand new Z. I just happen to look underneath my car and noticed rust on my exhaust flanges. Is this normal? Or should I take it back to dealer and have it treated. Also some surface rust that seems normal on other areas; but it’s not too bad. Car has 120 miles on it. Bought it brand new from dealer.

 

[Thefunk]

I also have rust. It's normal unless the rust is very deep to the point where pieces of the metal are falling off. The dealer won't do anything about rust (for free at least). You can buy some rust prevention spray and apply it to areas that show some rust. You may have to sand and clean those surfaces before applying the spray.

 

[Kelvin]

Thanks!!! Really appreciate the info. That’s what I will do. Again, really appreciate the info.

 

[FSUZ33]

You can buy "rust converter" as a paintable liquid or in spray cans that converts the rust and makes it inert (nonreactive) and it actually protects the original rusty spots against future rust. The rusty spots will turn black. I believe some converters don't need to be washed off before applying preventer, just need to be dry. I'm not familiar with the prep needed before applying a preventer (like degreasing, etc...).

Edit: I did just read that you should NOT use "converter" on clean (not rusty) metal as a preventer.

 

[Kelvin]

Thanks. I just used some rustoleum high heat rust stop spray. Also, dealer said
they will look at it during my first oil change.

 

[bonogoesfast]

I had the same issue on my 24 Z with the exhaust. I sprayed a light coat of CRC 656 Marine on the back exhaust section and worked it in with a rag, then wiped off all the excess. As for the surface rust on the other areas I plan to apply some black spray paint. I feel like there should not have been any rust on a brand new car, but sounds like this is not something unique to my vehicle.

 

[takemorepills]

I have a brand new Z. I just happen to look underneath my car and noticed rust on my exhaust flanges. Is this normal? Or should I take it back to dealer and have it treated. Also some surface rust that seems normal on other areas; but it’s not too bad. Car has 120 miles on it. Bought it brand new from dealer.

Don't look up under your dash or seats. In all cars, these areas are at least partially covered in surface rust.

In the late 80's through the 90's many manufacturers, if not most, used stainless steel in the exhaust. I have a 2003 Acura with the original exhaust, no rust. My 2007 Titan I used to have, the exhaust rotted off in less than 10 years. Nearly every manufacturer is now using regular steel in the exhaust system (there's a few still using stainless, but definitely not Nissan!).
In fact, speaking of Nissan, quite often the exhaust on a Titan would rot off below the rear frame harness, tip up and cut through a bunch of the harness wires, causing all kinds of faults.

So, it's normal these days. Those flanges will never rust through completely, the main concern is the weld joint of the thin exhaust tube to the flange. That's where it'll break over time. However, on these FM platform cars, it's very rare to have any significant issues, even after many years. The rust is ugly, but won't affect much for a very long time

 

[Kelvin]

I have a brand new Z. I just happen to look underneath my car and noticed rust on my exhaust flanges. Is this normal? Or should I take it back to dealer and have it treated. Also some surface rust that seems normal on other areas; but it’s not too bad. Car has 120 miles on it. Bought it brand new from dealer.

Thanks for the info. Really appreciate it. I did take it to the dealer and they sprayed some high rust proof application to the flanges; it came out pretty good and it really makes a difference in aesthetics.