2005 Polo GTI makes a loud whining sound on cold start - video supplied

[Neonistra]

Hi all,

Fairly new here so forgive me for any mistakes I may make. I have been having an issue where on start up, my Polo makes this horrific whining noise (see attached video). Doing some research online, some suggest it may have to do with the secondary air pump and I think from memory the mechanic said it was the air pump for the catalytic converter (though didn't go into much more detail than that).

It generally happens when starting from cold and will shut off after approximately 30 - 45 seconds, then will spin up again a minute or 2 later for another 15 seconds.

Is this a common issue, what is going wrong with this?

Attached Video

Thanks in advance for any help!

[JTop]

Definitely what you mentioned, heard it one too many times.
Unplug the Secondary Air Pump located under the intake manifold. It's the one that the two plastic hoses go to on the right hand side of the engine. One from the air box and the other to a combination valve.
The plug is located awkwardly at the back of the pump next to the dipstick tower. Those hoses once they break are silly expensive to replace. so press the two release tabs(180degrees from each other) firm and wiggle until each one pops off.
The three allen key bolts up the top of the manifold(in a triangular shape) allow you to drop the pump so you can turn it to unclip the tab. OR remove the dipstick tower and most probably have it break on you, so buy a new dipstick tube($26 from VW) if you chose to do that.

Once you got it disconnected give it a start. You will get a check engine light, which will equate to blah blah incorrect flow. A simple 300-400ohm resistor on the N112 valve under the engine cover(the other one, N249 goes into your diverter valve, leave that alone) will keep this from occurring.
The long term solution is to remove the entire system as it's only used for cold starts in the morning. That's about it.
Hope this helps

[Neonistra]

Thank you for this JTop! Certainly looking at giving this a try shortly - will update with my progress

For the long term solution, is it best to try and source a new Secondary Air Pump and replace it, or will the trouble soon outweigh the difficulties there?

[sambb]

I can have a dig under the house for a spare genuine one. If you buy new genuine they are expensive. You could probably get a stage 1 tune that deletes the function of that pump for the same money.

[JTop]

I always say, check for yourself!
Take the part numbers from each of the items, 06A-xxx-xxx stamped on them somewhere
Go to any VW Parts department, and ask for the full list
You will get a heart attack haha
I've got 3/4 pumps, 1 set of decent tubes left(my father stepped on one that was in a tub...), 3/4 N112's and 2 combi towers all as spares in case someone asks for it. PM myself or Sam
Need to sit and bench test all the parts

[h100vw]

Is the car stock or tuned? I can assist if stock. And you can meet up with Samb