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-   -   Secondary Air Pump (https://forum.a8parts.co.uk/showthread.php?t=15515)

Norretal 14th February 2020 08:59 PM

Secondary Air Pump
 
I had a trawl through the forum to see if anyone had experienced the same problem I'd been having and found very little, so I thought I'd share my findings which may benefit someone else in future.

A while ago my car developed a "noise" which was more of a whine. As I'd previously driven it home when the power steering system blew a hose I assumed it was the pump on it's way out as it's fatal to run them dry. Recently the noise got a lot worse and became more distinctive and I pinpointed it to being during start-up and ceased once the revs died off.

Onto the forum I go, D3 tech dump (thanks, again, Del +++) searching through the manuals and service information and discover the secondary air pump, whose failure suited the symptoms of what I was experiencing. Spoke to Prestige, bought a second hand one for £40, delivered next day (compliment in associated thread :) )

I had it fitted on Wednesday by my ever reliable mechanic, £30 charge, car now sounds like it should again. He confirmed the pump damage was internal, seemed like the pump vanes were damaged and it had become unbalanced, causing the noise. He also confirmed it looks like the same pump that's fitted to VW Polo 1.4 variants etc so it may be worth checking compatibility should anyone need one for an 8 and Prestige don't have one.

So, back on the road again, at least until the next mechanical episode...

steamship 15th February 2020 11:33 AM

Quote:

Originally Posted by Norretal (Post 155655)
He also confirmed it looks like the same pump that's fitted to VW Polo 1.4 variants etc so it may be worth checking compatibility should anyone need one for an 8 and Prestige don't have one.

The part number is 06A959253E and is indeed found in the Polo. In fact, it has been used extensively throughout the entire VAG range, so finding one should be easy.

Found in the following:
Audi: A3,A4,A6,A8,Q7,TT VW: Beetle,Caddy,Golf,Jetta,Passat,Polo,Sharan,Touran, Touareg
Seat: Alhambra,Altea,Cordoba,Exeo,Ibiza,Leon,Toledo
Skoda: Fabia,Octavia,Superb

HPsauce 15th February 2020 12:36 PM

Quote:

Originally Posted by steamship (Post 155661)
The part number is 06A959253E and is indeed found in the Polo. In fact, it has been used extensively throughout the entire VAG range

What about the D2 Sean, do you know offhand?

steamship 15th February 2020 01:22 PM

Quote:

Originally Posted by HPsauce (Post 155665)
What about the D2 Sean, do you know offhand?

Afraid not Andrew. Seems to have first appeared in VAG models from 1999, but for the A8, it was only used in the D3. The part number for the D2 one is 078906601F and was only used in the D2 (and the '03-'05 RS6).

EDIT: Forgot to say, the D2 one only has one pipe connected to it, whereas the D3 has two, so doubt they could be 'made' to work.

tonupkid 16th February 2020 04:23 PM

What is this secondary air pump for, what does it do?
I have a slight whine on mine, that I've always put down to the PAS reservoir being so hidden as to not get checked during regular services. (I make certain that they check it, but the former owner will not have). Perhaps this is the thing that's causing it. D3 S8

HPsauce 16th February 2020 04:37 PM

It's all to do with pollution control, by injecting air into the exhaust. Fairly complex as it works differently as the engine & catalyst warm up. See: https://en.wikipedia.org/wiki/Secondary_air_injection

Norretal 16th February 2020 05:40 PM

Quote:

Originally Posted by tonupkid (Post 155699)
What is this secondary air pump for, what does it do?
I have a slight whine on mine, that I've always put down to the PAS reservoir being so hidden as to not get checked during regular services. (I make certain that they check it, but the former owner will not have). Perhaps this is the thing that's causing it. D3 S8

That's how my suspicions started, thought it was the PAS pump and then realised it wasn't when it got worse and I researched it.

Get it replaced before it gets worse, it's not an expensive job +++

MikkiJayne 16th February 2020 06:23 PM

Quote:

Originally Posted by tonupkid (Post 155699)
What is this secondary air pump for, what does it do?

Its a total waste of space, weight and complexity to reduce emissions for a tiny part of any given journey. All it does is blow fresh air down the exhaust to heat up the cats faster by feeding them excess oxygen. I threw it all away on my S8 and maybe one journey in ten the ECU will get in a grump about it, and thats only because it's EU4. FL1 cars with EU3 don't care. Over the life of the car I doubt very much that the tiny impact it has on emissions will come even close of offsetting the extra fuel required to carry around several Kg of pointless junk.

Also, the amount of swearing it evokes when trying to get to anything on the back of the engine (which is all blocked by said pointless junk) probably contributes more to global warming than warming the cats up 60 seconds early ever saved :ROFL:

Its another case of manufacturers making something to pass the test, rather than making any useful contribution to real-world emissions.

Delboy 16th February 2020 08:14 PM

Will the cats be ok during that phase?

I thought the ecu chucks extra fuel through and the air pumps in the air to get the cats up to temp quicker.

Without air surely the extra fuel would be bad for the cat???

tonupkid 16th February 2020 09:45 PM

Thanks for the explanation folks. Enquiry now waiting with Prestige for when they open their inbox.
Car is in for its annual service soon, so a perfect time to get this investigated.


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