I have a Green cotton air filter. I have had it for about 6 months. I took it out to clean it and noticed brown burnt spots and small holes that appear to have been burnt away. The rubber also appears to have been burnt. This is very strange to me as everything else is stock other than the plugs and wires. I have about 97000 miles. I don't see how a back fire could make it all the way to the air filter. The outside of the air box is fine, but the inside seems a bit charred on one side. There is no carbon deposits, just melted plastic.

This can't be normal on a stock car...what does this mean?

 

Sounds like your car ingested a cigarette butt or some embers from a fire. It's not as strange as it may sound. There have been documented cases of automobile fires caused by this.

 

+1

This is common when driving past brush fires. Firefighting equipment often has issues with air filters for the same reason..

 

Thanks for the input...one more thing that I might add...

The burns were on the top of the filter...it seems to me that if it sucked something up, that the burns would be on the bottom...

There have been an insane amount of fires around here and I was having some fun near big cypress where that are some very large fires right now.

It doesn't sound that strange though...despite the 500,000 acres of fires in FL right now, people love to throw cigarettes out of the window.