Audi6spd

<center><img src="http://pictureposter.audiworld.com/79460/a4_engine.jpg"></center><p>I'm looking at purchasing an '03 1.8T (MT) but there is a space in the engine bay that is missing this round shinny component. Can anyone tell me what this component to the left of the yellow arrow is?

x1rider

it has to do with the automatic transmission (not present with MT)

skeeball

AFAIK, only auto trannys have it.

HeartlessNomad12

I was wondering the same thing on my 02 3.0Q MT6

Audi6spd

Ya'll are awesome, thanks!

diagnosticator1

The vac pump maintains the vacuum in the brake booster above the minimum required value.

diagnosticator1

Apparently, all 3.0's have one, but on the 1.8T, only with Auto box.

skeeball

I don't have it. But it might have been removed when the blower was put on.

Mrkrad

the tiptronic shuts down the DBW at 2500rpm if you are trying to brake stand the car. not sure if the manuals do that too. quite annoying

diagnosticator1

The 1.8T auto box needs it due to the EPC. During certain running modes, the throttle valve is opened a lot and engine rpm is controlled be the VVT and ignition timing. With the TV opened at low rpms, there is not much vacuum in the intake, thus the vac pump runs under ECU control when measured booster vac is to low.