Taken from uk-mkivs.net, this a very comprehensive guide to repairing the secondary air pump on the 1.8T engines. This can be applied to Audi, Skoda & Seats.

Quote Originally Posted by Albo (uk-mkivs.net)
The noise from my Secondary Air Pump when starting from cold had been getting worse and worse and was slightly embarrassing. It sounded like a very loud vacuum cleaner for 90 seconds, followed by a huge dump valve noise.

After reading on UKMKIVS about repairing the secondary air pump, I decided to repair mine today. I tried to search for a guide but couldnít find one, so here is mine.

The whole job took 2 hours. By far the longest part of the entire process was removing the pump from the car, especially getting to the Allen bolts. Putting it all back together was easy.

Tools used:
Trolley Jack
Axle Stands x 2
T20 Torx screwdriver
8mm Allen Key
10mm Socket
Flat bladed screwdriver
Electric drill with 4mm drill piece.

Parts required:
Six of each of the following:
4mm by 50mm bolts (I could have probably used 45mm long bolts but wasnít sure until I got to that stage. They donít get in the way of anything though)
4mm flat washers
4mm split washers

Step 1
With the car jacked up and supported by axle stands, remove the front splash guard from behind the front bumper. There are 4 T20 Torx screws.

Step 2
Remove the hoses from the air pump. There are two hoses, one is hidden in the picture. These are held on by plastic clips and can be pulled off whilst squeezing the opposite sides of the hose to the clips (RED ARROWS). If they get stuck use a flat bladed screwdriver to carefully work the clips loose (YELLOW ARROWS). Remove the electrical connector from the pump (BLUE ARROW). Use a flat bladed screwdriver to gently prize the clip open and the plug will come off easily.

Step 3
Undo the three nuts holding the pump to the bracket using a 10mm socket. This allows easier access to the bracket bolts (one hidden in picture)

Step 4
Reach just above the pump using the long end of the 8mm Allen key and undo the lower two bracket bolts. The bolts are separated by two or three inches. You can move the pump as necessary to allow easier access and visibility. You may need to add an extension bar to the end of the Allen key to provide more leverage. The diagram shows the direction and position of the bolts obscured by the pump).

Step 5
With the bracket held on by only one bolt you can push the bracket towards the passenger side of the car, allowing the pump to be extracted.
The following shows the separation of the pump allowing air to escape.

Step 6
Using a 4mm drill piece CAREFULLY drill each rivet until it breaks. The remainder of the rivet can be pushed out using the drill with it switched off.

Step 7
Replace each rivet with a bolt. Insert a flat washer then a split washer before the nut. The flat washer should stop the split washer from sinking in to the plastic casing and the nut working loose. You could also use threadlock in addition.

Step 8
Refit all the parts in the reverse order they were removed. Here it is finished.