# How to: 3.2 VR6 (BUB) Cleaning the Secondary Air Pump Filter



## SwissJetPilot (Apr 27, 2014)

While I was sorting out my new oil housing cap, I decided to take a look at the *Secondary Air Pump (SAP) Filter*, aka Check Valve, aka Non-Return Valve and see just how dirty it is.

*Note -*_ This is for a 3.2 (BUB) engine so your SAP plumbing may be slightly different. Some vehicles draw air into the SAP directly from the air filter box. Check the Workshop Manuals for your specific engine._

I looked up a replacement part and found *P/N 3B0131351* is not a cheap at €69.48 on Amazon! However unless it's damaged, there's really no reason to replace it. I couldn't find anything on this for service intervals and the workshop manual only states "clean if dirty". So that will depend on where you live and the roads you travel.

Getting the filter elements out to clean them is easy enough; just look for the alignment tab on the side and use a pry tool to get it apart then cover comes off quite easily as it snaps in place. There are two filter elements; one coarse and one fine and on top of those is the check valve, which is just a plastic ball. Use caution when you remove the filters so the ball doesn't fall out and roll away.

The filters are not glued together so everything comes apart as shown. Give everything a good wash and put it all back together. Note the alignment tab when reinstalling the cover.

While the entire assembly can be removed and from the SAP as shown here, there's really no need to. Plus it's a bit of a PITA to put it back in since you can't quite get both hands on it with the coolant hoses in the way. (Trust me on this!)

Also, while you're doing this, it's a good time to check the SAP *Rubber Mounts* as they can degrade over time.









































Here's the filter assembly removed from the SAP and disassembled on the bench. You really don't need to remove all this, I was just curious how it all went together -


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## SwissJetPilot (Apr 27, 2014)

There are a few fault codes related to the SAP which may include *P0410, P0411 or P0412*. If you've encountered deep water or really muddy roads, be sure to inspect the filter to make sure it's not blocked or damaged.

For a better understanding of the SAP and how it all works, this Youtube video is quite informative -

*Secondary air system - Basic information*






*Secondary Air Injection Systems on German Vehicles*






















From the Workshop Manual, the items discussed above are Items 18 and 19 -

*FAQ - Audi TT (8J) Workshop Manuals & Self Study Programs
3.2 Engine, BUB, CBRA, 3.2, 6-cylinder Injection, 3.2 ltr. 4-valve, Mechanics (A005TT01120)*
https://www.ttforum.co.uk/forum/viewtop ... &t=1833829


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## MT-V6 (Jan 11, 2015)

Is this something you have done to your car? Was the filter noticeably dirty?


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## SwissJetPilot (Apr 27, 2014)

Yes, this is my car.  And no, the filter element wasn't really that dirty. But I did notice some very fine dust inside the SAP intake tube (seen below). But for being 13-years old I can't say this is a concern.

However for people who live in very dusty areas, the filter elements are obviously not that effective. So a regular cleaning, or a replacement with a better filter might be in order. I suspect these are just there to keep the big chunks out and the ball keeps water out if you have to go through deep water.


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## BIGmog (Mar 15, 2015)

Troubleshooting an issue with Secondary Air Injection readiness monitor for emissions, I checked the filters on the secondary air pump. No significant dirt found but I cleaned them with soap and water anyway.

Thanks for the handy guide with great photos.

-Dusty


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## IPG3.6 (Sep 5, 2015)

Great guide! 
Although I have deleted and coded out the SAI on our 3.2 so it saves having these issues along with freeing up the bottom of the engine bay.


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## SwissJetPilot (Apr 27, 2014)

@ *IPG3.6* - Oh do tell! I'd love to be rid of mine. Just one more piece of unnecessary hardware IMHO. Is there much to it?


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## IPG3.6 (Sep 5, 2015)

You will need a SAI delete kit.

SAI delete kit and ensuring it doesn't leak

Then you will need to tune it out (of the software). Once you've downloaded the tune you will need to open it up in tunerpro or Winols. Values needed to adjust are in the ESKONF. Kind difficult for me to make a post on it but I'll try and link to relevant threads on where to find this map in the tune if you think it'll be useful?


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## SwissJetPilot (Apr 27, 2014)

You lost me at "_Then you will need to tune it out (of the software).._."  Probably waaaay too complicated and I suspect the local TÜV guys will catch it out come inspection time.


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## IPG3.6 (Sep 5, 2015)

Hahaha. Fair enough but it is definitely an option


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