Loud SAI on startup

[CaptainAwesome]

I'm not really sure on how everything with the Secondary Air Injection pump works. (because I hate it, and everything emissions related) But I have a new problem.

For the first 90seconds I start my car. I can hear basically open exhaust. It's LOUD.Responds to engine speed, and is not intermittent. After the SAI turns off, smooth as can be.

I thought at first it was an exhaust manifold gasket. But now I don't think it's that. The sound emanates form the upper portion on the left side of the engine when looking in the engine bay. It does not sound like it's coming from underneath the car or from where the SAI Pump is located. What parts of the SAI system might go bad that are closer to the engine block that would cause this noise? And for only while the SAI is running.
Anybody? Ideas?

[RecklessTuning]

the SAI pump is going bad. Thats what they do when there on there way out. It located on the passenger front of the engine bay by the radiator fans.

[MikeWire]

It's probably disconnected from your air box. Look for a black hose with a 90 degree connection that should connect to the hole on the front of your air box. Plug it in and it should be quieter.

[CaptainAwesome]

SAI pump was replaced 20k miles ago. I don't think it's that- definitely not the same problem I had before with it, although I could be wrong.

Airbox intake tube is securely connected.

[MikeWire]

Well, all I can say is that something is not hooked up properly if it's loud. If it's connected at the airbox, then you should get under the car and make sure you have both output and intake hoses securely connected to the pump, and that it's secured to the hard pipe on the intake side of the pump that comes down from the kombi valve. Also look for any splits or breaks in the hoses.

[CaptainAwesome]

Is it possible the Kombi valve could be toast? And what the hell is a Kombi valve? Where is it?

[old guy]

Is it possible the Kombi valve could be toast? And what the hell is a Kombi valve? Where is it?

Check where the air hose from the SAI connects to the silver combi-valve on the back of the head. If that line isn't connect you will essentially have an open port to the exhaust when the combi valve is open.

[nofearhawk]

Depending on the number of mods you have and if you plan on doing more, it might be worthwhile to just remove the SAI system and get rid of a large chunk of check valves, vacuum lines and connections where leaks can form.

This is only if your car is NOT stock and you have plans to do more than a chip. Also you'll want software to delete the SIA CEL.Just a suggestion.

I have random vacuum leaks in my SAI system and will be spending this weekend ripping all that stuff out cause I'm sick of these problems.

[bigblue]

The combi valve is supposed to be changed every time you change the sai pump... it could definitely be the problem.

[hardwarephreak]

I had my SAI pump go bad, replaced it. 1 Year and 2 months later it was dead again. The cause that they didnt catch the first time? That would be the water that followed the hose down to the pump and then pooled in it and seized it up again. Im not saying it is the problem, and Im not saying it's not the problem..Im just telling you that just becuase they fixed it 20K miles ago, doesn't mean they actually fixed the cause of the pump going bad to begin with.

Damn thing pissed me off too. Since it's an emissions part, pretty much you are screwed when it comes to a warranty/aftermarket warranty covering anything about it.

The best part about the emissions restrictions...it's one of the reasons that any audi with FSI has carbon buildup...because they have to recirc everything back into the engine where it causes the problems. Love emissions...LOVE IT. Of course I don't want to be driving around in a Los Angeles Circa 1960 kind of smog atmosphere either so I guess theres a little give and take to be had there.

[CaptainAwesome]

The combi valve is supposed to be changed every time you change the sai pump... it could definitely be the problem.

Is this something the Dealership would do if the SAI pump was replaced under warranty? I honestly don't think they did.

The more and more I think about it, and where the sound is coming from - The problem is most likely exactly what Old Guy said. I can see the hose is connected to the Kombi valve. but I did not make sure that it is secured.

Trust me - if the pump went bad again I'd just be ripping it out and getting chipped.

[bigblue]

Ok... Well you can follow the hose from the combi valve, down the side of the block, around the turbo inlet pipe, down to the sai pump. Then from the pump up to the air box. Make sure all those connections are good. I mean a good way to check the hose on the airbox would be to unhook it I guess and blow into it and listen for air escaping? I've got two of these pumps for sale that are good as I don't run them on my cars.

[CaptainAwesome]

Figured out what it was - So the rubber elbow hose at the front of the engine on the left side, connecting the egr pipe from the exhaust to the combi valve in back of the engine was torn. And not in a way that you could visually see it. It was sliced exactly on the seam where the hose clamp was, so I couldn't see it at all.

Got this replacement Silicone Hose from 034 and it worked perfectly!

http://www.034motorsport.com/engine-...e617gh2bna2g02