# DIY: Rebuild your whiny Secondary Air Injection pump



## evilpat (Feb 26, 2002)

*DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump*

Sorry no pics this time around . . . yet. If anyone has any pics they want to donate that would be great!
Diagnosis: Loud whine on cold start or when ever the secondary air injection pump turns on. You should be able to get under the car and look at the pump and you can physically see the aluminum rivets holding the fan housing coming apart. Sometimes it is not that obvious so look closely.
Solution: Replace the pump which is hundreds for a new one or buy a used one that will likely have the same problem eventually . . . or rebuild the one you have and make it better.
Required:
8mm allen socket with a short and long extension
10mm box wrench (ratcheting even better)
Drill and set of drill bits
Scratch awl
Flash light
6x 8-32 1 1/2" long non-corrosive pan head machine screws with self locking nuts (I found some SS ones at a local hardware store)

*Removing the pump* 
(1) Jack up the car and remove the belly plate. From above reach down and remove the two hoses coming from the inlet and outlet of the air pump. They will be a pain in the a$$ if you have never removed them before. They clip on two sides and you must pinch between the clips to force them out. Hard to explain but fairly obvious if you look at any of the other hose fittings through out the engine bay. I added a little grease when I reassembled to help if I ever had to remove them again.
(2) from under neath the car disconnect the electrical connector from the back of the pump (facing the driver's side of the car on the transverse 1.8t)
(3) using the box wrench loosen the three 10mm nuts holding the rubber bushings to the steel mounting ring. There are two that are easy to get at but the third is on top. I was able to get at it with the wrench just feel around till you find it. The mounts are just rubber bonded so be careful not to tear them.
(4) From above use the flashlight to find the first of three socket head bolts holding the steel mounting ring to the front of the block. Easiest way to find it is to look directly past the oil dipstick tube. Get in there with the 8mm allen socket and the long extension and remove the bolt.
(5) From underneath you look between the pump and the oil pan to find the remaining two bolts with 8mm allen and the short extension. With the pump loose in the ring it is easier to get at those two bolts. Once removed the pump and support ring will easily come out.
*Rebuilding the pump* 
As long as the pump has not failed it can easily be rebuilt in a few minutes. The "whiny" pump is caused by the failure of the 6 aluminum rivets holding the fan housing together.
(1) To clean the pump plug the inlet and outlet of the pump with a silicone plug (or something similar) and spray the housing of the pump down with a little simple green. Scrub on it a bit and gently rinse. Be careful and try not to get water into the pump through the inlet or outlet or where the housing is coming apart.
(2) Remove the 6 aluminum rivets by inserting the scratch awl into one end the rivet and using a drill bit to remove the head on the other side. Switch sides to remove both heads of the rivet. You can also remove one side and try and push it out.
(3) Insert the 8-32 pan head machine screw through the holes and secure with the lock nuts. If you want to make sure it never loosens up add a little bit of high temp thread lock.
Admire your work and then reinstall reverse of removal. If you want to test it hook up some repair wires to a 12v source. Power wire is usually striped, ground is usually solid brown.










_Modified by evilpat at 3:00 PM 3-24-2008_


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## evilpat (Feb 26, 2002)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (evilpat)*

20v18t rebuilt his without even removing the pump if you do not feel like removing it. Just loosen the 3 nuts holding the pump to the support and rotate it and remove the old rivets. Even easier!


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## 20v18t (Apr 9, 2002)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (evilpat)*

Yes I did








Thanks for the great write up!


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## RvGrnGTI (Apr 13, 2005)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (20v18t)*

Awesome! I honestly haven't really cared to fix it, but if it's that simple and cost effective... why not! http://****************.com/smile/emthup.gif


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## evilpat (Feb 26, 2002)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (RvGrnGTI)*

as long as it spins freely and the seals are good it is that easy


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## 4father (Jul 12, 2002)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (evilpat)*

gotta be honest w/ you guys... this DIY is a total pain in the arse!!!! 
Having said that... i replaced the 2 failed rivets w/ screws and the whiny noise is gone. I know... i should have replaced them all, but during the operation, i found that my drill is in storage, so i couldn't get them out.
thanks for the DIY... saved me $400!!!!


_Modified by 4father at 7:28 PM 4-4-2008_


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## powdercrazy (Jul 16, 2005)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (evilpat)*

so thats what that whining sound is?


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## bpfoley (Nov 30, 2000)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (powdercrazy)*

I did not need a drill to remove my rivet, I just hammered them out with a punch which turned out to be very easy. I also left it in the car and rotated it in place. Total repair time was about 30 minutes start to finish. It was also a proactive fix as my pump was still silent.


_Modified by bpfoley at 8:21 AM 6-22-2009_


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## XClayX (Apr 30, 2005)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (20v18t)*

Might be added to Tuesdays schedule coming up.


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## xpxhxoxexnxixxx (May 17, 2007)

*Re: DIY: Rebuild your lound, noisy, whiny Secondary Air Injection pump (XClayX)*

good diy im gonna try it for sure


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## Appleseed (Aug 1, 2011)

Sorry to reawaken this thread. But could a squealing pump cause a CEL?


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## radlynx (Jan 4, 2007)

no, you have some other issues.



Appleseed said:


> Sorry to reawaken this thread. But could a squealing pump cause a CEL?


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## Appleseed (Aug 1, 2011)

radlynx said:


> no, you have some other issues.


Blast.. Thanks


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## Slimjimmn (Apr 8, 2006)

step 1- buy 4mm 2.5" bolts and nuts
step 2- put bolt through rivet hole and tighten with nut
step 3- repeat for all rivet holes

done


FYI the new "updated" pumps at the dealer have this done already:thumbup:


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## Ubervier (Nov 4, 2012)

I used this set of 1.5" bolts, washers, and loctite, did the fix last night. I chose to take my pump out and that was a huge pain. It's probably easier to leave the pump in, complete work on the accessible rivets, rotate the pump and re-secure it, work on 2-3 others, repeat. Dead silent pump now, worked out wonderfully. My pump had only a very tiny amount of space.

http://www.walmart.com/ip/Bulldog-Hardware-10-x-1-1-2-Machine-Screws-7pk/17474130#Item+Description


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## Cableman (Jun 15, 2008)

Thanks for posting the writeup. I used your directions as well as this other writeup with photos.

I had literally completed replacing my PCV hoses, got everything buttoned back up, and went to take the car for a test drive. Upon starting it, I heard the dreaded whizzing noise. Luckily in my research on the PCV hose problem, I came across the mention of the air injection pump wearing out and making a noise on cold starts. After getting the pump out, I was relieved to see that the head of one of the aluminum rivets was _gone_, the other rivets had appeared to stretch/deform a bit, there was a noticeable gap between the two halves of the pump housing. 

I encountered one problem. I used 8-32 1 1/2" screws as specified, but they were just _slightly _too short. The threads would not have made it all the way to the nylon inserts in the nuts, so I didn't want to risk it and do this job again. They needed to be 1/4" longer. I will pick up a pack of 2" screws, which is probably the best I can find on short notice in stainless steel. I will attempt to complete the repairs tomorrow. Also, I ended up removing the whole steel bracket that holds in the pump. Once I figured out how to get the top bolt out (aim for the top of the dipstick tube), and I had the correct length ratchet extension, it came out without too much trouble. The biggest difficulty was that the bolt head was full of crud which made it difficult to get the 8mm wrench in fully. It's an impressive bracket, design wise. I will post some photos after I get everything back together.


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## Cableman (Jun 15, 2008)

I was able to successfully rebuild my air injection pump using the above described procedure. Here are some photos and commentary from my work:

I ended up removing the whole pump bracket, and reinstalling it took some patience. You need the right 8mm hex socket and a variety of ratchet extensions. In particular, getting the top bolt reinstalled took some practice. While working under the car, I was able to reach up between the fans and various hoses and manipulate the socket extension and get the bolt threaded in. Then later when you're ready to tighten that bolt all the way, position a small flashlight so that it illuminates the bolt in question from below. Then, you can work from above. If you look down the passenger side of the dipstick holder base, you will see the bolt. Then you can get your socket and extension into the bolt head. The other challenge was getting the passenger side lower pump bracket bolt (one of the 3 total bracket bolts) threaded in. Working from below, you can see generally where the bolt will go above the pump, but you can't see the actual hole. I could feel it with my finger but couldn't see it. I used the 8mm hex head socket and a medium extension and guided the bolt in place, but it was difficult to get it to thread. Finally, I tilted the socket/extension up a bit higher and that was the right angle to get the bolt to thread in, finally.

If I did the work again, I would avoid removing the pump bracket if at all possible, but I know I would at least need to loosen the top mounting bolt and remove the lower two.

One of the aluminum rivet heads was totally missing, shown below:










Below we see the gap between the two halves of the pump housing:










I ended up removing the pump bracket. Here we see one side of it:










Here's the other side. You can see the 3 bolt holes. The two holes on the cross piece are location just on top of the pump when it's installed. The third hole goes further up on the engine block:










Here's the pump in the bracket as it's mounted on the pump as it would be in the car:










After drilling out the rivets and installing 2" screws, I realized that one was sticking out in a way that might have impeded the reinstall of one of the bracket bolts. Here we see the offending screw before cutting:










Thanks again to the OP for posting the writeup.


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