paalw

One day last week when i started up my S4 Auto I got a whining sound from somewhere someplace. it changes accordingly when revving the engine. It is not loud, and is most noticable on low revs in 1. an 2. gear. when cruising in D it is nearly not noticable.

I thought I would start with removing the air pump belt(my cats are gone anyway). Therefore i wonder:
On an S4, is it just to cut it off and leave everything there?
(then maybe later pull out some more)

BPG_Austin

I cut my belt off months before removing any plumbing with no ill effects. While doing some engine maintenance I removed all the smog equiptment and welded shut the air line from the exhaust. (I'm running hi perf cats that don't require air) I think its pretty common, hopefully others will chime in.

BG.

AO

There is a vacuum actuator near/below the windshiled washer filler neck that you should probably pull the small vacuum line from and plug (the line, not the acuator). Many people just use a small machine screw with a zip tie to plug it. Other than that, you can leave everything else. The only thing it hurts is the weight.

AO

Thanks to Tony...

Pull the line going to #12. Edit: I see he labeled the line #22.

WallyP

The most common whine is the power steering pump...

The_Remora

If you remove the air-pump, keep the air-pump bracket that holds the pump and retain it as a spacer for the a/c condenser. If you do not then the a/c assembly will be out of alignment and the belt will be prone to jump off of the pulley. Or you could fabricate a spacer that is the same thickness of the air-pump bracket. The important thing is to keep the a/c belts alignment as it was designed to be or you will run into trouble.

cold_beer839

I just cut my belt and left all the other stuff (x-pipe no-cats). I still need to plug that vacum line AO mentioned (didn't know about that).

paalw

Thanks a lot guys! as always, no problem to get answers here

Just to be totally sure, do anyone have a pic of what belt to cut, so I dont do anything stupid? hehe. (i found a pic but that was an older model so...still only 99% sure)

sendarius

When I got my '88, the air-pump had been removed but the bracket and other stuff was still in the car. The pipe from the pump was plugged with a ...

wait for it ...

spark plug!

LeRox

Mine got cut off at SITM, due to the air pump bearing making more noise than the sweet idle sound of the motor. (Thanks to the TEXAS CREW for the belt cutter, NICE)…

Have yet to plug the vacuum line (see post #4) and may get to this evening.

aggravation

Here's a diagram, on my '88 S4 it's the belt to #3.

paalw

there you have it. thanks. thats what i thought.

only difference we dont have no.2 right?

Bill51sdr

No. 2 is the clutch fan pulley on pre S4's.

paalw

removed the belt, but of course sound is still there. Whining is actually best heard from the coupe. Easy to hear in N between 1000 and 2500 rpm. Not that easy to hear from outside with the bonnet open.

I see wallyp says most common thing is power steering pump. What to do? Cut that belt too?