YT1

Had my 88 S4 out for a leisurely Sunday spin yesterday. A few blocks from home I smell a burning odor, I proceed through the light and smoke is billowing from under the hood. I don't smell fuel but obviously that is my first thought. I was terrified to loose my car but by the time I get pulled over, no fire and no more smoke. I drive the car home and can't locate the problem. I run the car with no leaks or drips and finally find the empty pulley. It took me a while to ID that it's the air pump on the passenger side sitting above the AC compressor. The pulley seems siezed and the belt is gone. I guess I'll replace the pump because I used the air pump bracket with my PKT install. Will it hurt to drive the car like this? How urgent is replacing it?

Ducman82

won't hurt a thing.

Adk46

California and a few other parts of the country will want to see that belt going 'round and 'round during inspection. You're fine otherwise. If you need a pump, there are plenty kicking around loose - I have two myself.

docmirror

You gain ~4HP with the belt off. Unless it's needed for smog inspection, just leave it off, or remove the pump and the filter housing and lose a few Lbs.

davek9

This sound like a CAT Fire in the making, are you sure the car is running on all 8 cylinders?

Strosek Ultra

I have deleted the air pump in all my cars. Over here these cars are so rare that no smog inspector will know if there should be an air pump present or not.
I have also deleted the catalytic converter for two of the cars (the third did not have one) which I did before the cars (private imports from Germany) were approved and registered in the country. The cars did get an approval as non cat cars which many people find hard to believe it can be done.
Åke

YT1

99.9% it was just the belt roasting when the pump siezed up. There are little charred bits of the belt on the pulley.

Koenig-Specials 928

I have been running without the air pump for 10 years now.

Avar928

The air pump is essentially useless these days aside for smog testing in certain states with very restrictive requirements.

I'd take mine off if my X-pipe didn't have the port. One day when I disassemble I'll have it welded and take out all the plumbing associated with the air pump.

Jherriott

One of the first things I did after a squealing start-up one day... *SNIP*! Problem solved.

YT1

Thanks for the help guys. It's nice to finally have an issue with the car that won't cost a fortune or cause a headache!

Crumpler

I had the same experience early in my ownership of the 86.5. In fact, I was trying to convince my wife that I had made a sound purchase, took her out for spin and I got this belt fire from the air pump freezing up... I pulled the pump out the next day.

I was expecting somebody to speak up on an eco friendly protest....where's Alan anyway? I haven't seen him posting for awhile, now that I think about it.

The Forgotten On

The air pump only helps to reduce emissions while the cat is warming up (provides extra O2 to help burn fuel).

Otherwise it doesn't affect anything after the car has been driving for 5 minutes.

I'm relatively eco conscious but I don't really view a need for it. The cat on the other hand....