phaeacian

Burnt may actually be an understatement... about half of the filter was literally gone.




I picked up this Type 44 Audi 100 in spring. It's the first time I looked at the air filter, and it's a mess in there. The inside of the air box is also melted in some places.

I went ahead and replaced the filter and cleaned the inside of the airbox (lots of dead bugs), and now it actually idles worse than before. Any idea what's going on here?

Thanks!

toml99

Best guess, the rest of that filter is somewhere in your intake, and with the new filter, you're not getting enough air....Otherwise, maybe you've got some burned wires....either way, there's most likely something(lot of something) in that intake.....

audi_marv

The idle was probably adjusted to get it to run also....and now that you have a whole filter in, its out of whack. The manifold is right there at the airbox, so is any of the heat shield even left ??

phaeacian

Heat shield? Not sure... the car is throwing different codes every time I run it, though...

2122, 2122, 2322... I'm wondering if it's a vacuum leak somewhere. The carbon canister solenoid clicks like crazy if I turn the key to "on" but don't start it. Otherwise, sometimes it idles fine on cold start. Sometimes it idles like crap on cold start. And once the engine is warmed up, the idle just mysteriously drops and surges at times. Very weird.

audi_marv

Sounds like a vacuum leak, and/or your idle stabilizer. Pull the stabilizer and clean with throttle body cleaner, as it may just be sticking. When idling, remove the oil cap and see if the engine dies (it should). If not...its getting air from a leak somewhere. The buzzing with key on is normal. Its not your canister, but the other cycle valve thing that's right there by the fender and airbox that I can't think of the name right now.

phaeacian

Thanks! I'll give that a shot tonight... trying to get as much done before the weather turn cold.

richard-tx

I have seen burnt air filters caused by the use of starting ether and a backfire. What happens is the ether is sucked in, then the backfire occurs with the flame front following the path of the ether to the air filter. This flame ignites the air filter. Standard repair procedures will fix the damage.

Pushbutton_auto

Yeah, clean everything out, including the throttle body, check the piping and sort any vacuum leaks.

Adjust the idle (screw it in and back out a couple of turns), the computer will cover any small variations.