1

I took a look under the hood of my friend’s car and saw this colorful coil:

Colorful coil

What is this?

3

It's part of the exhaust. Most likely it's part of the exhaust gas recirculation (EGR) system. The part you are pointing out is a part which allows a bit of flex without any damage coming to the tube as a whole.

3
  • Why does it have this color?
    – hb20007
    Aug 28 '21 at 22:01
  • 2
    Because it's been heated and the type of metal it's made out of, I'd assume? I'd bet the metal is a bit softer than the regular exhaust pipes to allow it to flex better. This may have caused the color. It's definitely nothing to worry about. Aug 28 '21 at 22:05
  • 1
    It is stainless steel . the color is heat tint caused by different thicknesses of oxides. Just like a motorcycle stainless exhaust. Least thickness ( lower temperature ) gold . then pink, then pinkish blue, then blue , then purple ( thickest = hot). Then it will turn black if the oxide is thick enough. Steel goes through the same color range at much lower temperatures. Aug 29 '21 at 16:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.