Loud whining at start up. Video included.

[ecjr173]

Hey guys, so i keep getting this loud whining sound when i start up my car. It last for a couple of minutes then goes away for a few seconds and comes back for about 7-8 seconds. Then it goes away. I won't hear it again until i restart it the next day or after its been off for a few hours. You can hear it more the second time the whining starts around the 2:10 mark of the video. Any help on what it can be would be appreciated. Thanks

[old guy]

Secondary air pump. It runs for about 90 seconds during a cold start and shuts off. Then 45 seconds later it cuts back on for a short interval. The second time it runs is when the ECM performs a rationality test to make sure it is working properly.

Are you getting any DTC's such as a P0411?

[ecjr173]

Secondary air pump. It runs for about 90 seconds during a cold start and shuts off. Then 45 seconds later it cuts back on for a short interval. The second time it runs is when the ECM performs a rationality test to make sure it is working properly.

Are you getting any DTC's such as a P0411?

Im not getting any codes or CEL. I have only scanned it with my buddies OBD II scanner and cleared some misfire codes. Other than that nothing.

[old guy]

You definately need to replace the SAI pump. You also need to check your combi valve on the back of the head. During the SAI cycle the combi valve opens and the SAI pump blows additional air into the exhaust stream. Once the cycle is complete the pump shuts off and the combi valve closes.

If the combi valve is defective and doesn't close completely what happens is that moisture from the exhaust will collect in the SAI hoses and eventually it gets into the SAI pump. This rusts the pump out from the inside and it starts howling.

You could just have a defective pump. But I would guess that probably half the time when the pump goes bad you will find water in it from a stuck combi valve.

[ImAudiHeree]

Also check for the secondary air hose i had the lower one that connects to air pump disconnect and it made some pretty beautiful sounds like that one did.

[ecjr173]

How difficult is it to replace the SAI pump and combi valve. Is there a DIY for these.

[userbob0001]

This is the DIY to remove a lot of the stuff. Install is the reverse of removal. It's annoying work because of the confined spaces. The Combi bolts are allen head but it's too tight to get a ratchet back there. I broke one of those cheap ratcheting offset bit drivers doing the removal because the bolts are in there really tight. Getting the valve off of the bend below it isn't fun either because it's another one without enough space to get a large wrench onto.

[OldmanRacer]

How crucial is the SAI pump for safe operation? Mine going bad too and I read somewhere I think that its not required and that most cars don't have such a system?

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[SJorge3442]

How crucial is the SAI pump for safe operation? Mine going bad too and I read somewhere I think that its not required and that most cars don't have such a system?

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Its not anything for safe operation. Plenty of people delete them, but its checked off as a required emissions requirement for our vehicles, so those of us in the USA need the system in place to properly pass inspections. All its job is, is to pump clean air into the exhaust on startup (fuel mixture is richer, thus exhaust is dirtier) so that the overall exhaust isn't as toxic.

[OldmanRacer]

Its not anything for safe operation. Plenty of people delete them, but its checked off as a required emissions requirement for our vehicles, so those of us in the USA need the system in place to properly pass inspections. All its job is, is to pump clean air into the exhaust on startup (fuel mixture is richer, thus exhaust is dirtier) so that the overall exhaust isn't as toxic.

To remove is simply just unplugging and removing the pump?? Would it throw a CEL?

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[ECS Tuning-Audi]

^^ You'd also want to get a block off plate for the combi valve.

Jason

[old guy]

Yes she will get a code P0411 for an incorrect flow. You will probably also get a code for the pump itself.

[customa4]

This is the DIY to remove a lot of the stuff. Install is the reverse of removal. It's annoying work because of the confined spaces. The Combi bolts are allen head but it's too tight to get a ratchet back there. I broke one of those cheap ratcheting offset bit drivers doing the removal because the bolts are in there really tight. Getting the valve off of the bend below it isn't fun either because it's another one without enough space to get a large wrench onto.

Just put an 8mm box wrench on the Allen wrench and use the box wrench for leverage.

[WOT]

Hey guys, so i keep getting this loud whining sound when i start up my car. It last for a couple of minutes then goes away for a few seconds and comes back for about 7-8 seconds. Then it goes away. I won't hear it again until i restart it the next day or after its been off for a few hours. You can hear it more the second time the whining starts around the 2:10 mark of the video. Any help on what it can be would be appreciated. Thanks

Sounds like a leak of some sort. Are you loosing boost? Is the car driving weird?

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[WOT]

Secondary air pump. It runs for about 90 seconds during a cold start and shuts off. Then 45 seconds later it cuts back on for a short interval. The second time it runs is when the ECM performs a rationality test to make sure it is working properly.

Are you getting any DTC's such as a P0411?

Delete it from your entire system and code it out.

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[WOT]

To remove is simply just unplugging and removing the pump?? Would it throw a CEL?

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Yes it will so, code it out and get a block plate for where the combi valve goes.

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[ecjr173]

Sounds like a leak of some sort. Are you loosing boost? Is the car driving weird?

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Nope. Runs really good actually!!


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[WOT]

Nope. Runs really good actually!!


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Check for boost leaks, do a boost leak test

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[old guy]

Check for boost leaks, do a boost leak test

That noise isn't coming from a boost leak. It is definately related to the SAI system. Either a defective SAI pump or an open line between the pump and and combi valve.

[WOT]

That noise isn't coming from a boost leak. It is definately related to the SAI system. Either a defective SAI pump or an open line between the pump and and combi valve.

Well that's not hard to check...

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[userbob0001]

That noise isn't coming from a boost leak. It is definately related to the SAI system. Either a defective SAI pump or an open line between the pump and and combi valve.

Yeah, the way it all stops right around 90s is pretty solid proof

[old guy]

Also check for the secondary air hose i had the lower one that connects to air pump disconnect and it made some pretty beautiful sounds like that one did.

I don't want this response to get lost in the thread. Whereas I have been pointing the finger at the pump it could be as simple as a loose hose.

Although I would expect a loose hose would cause a DTC for an incorrect flow.

[ecjr173]

So quick question. Where's a good place to get a pump. Besides the dealer.


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[old guy]

Check in the classifieds. There are several part outs going on. You can probably get one there for a reasonable price.

[seanf86]

So quick question. Where's a good place to get a pump. Besides the dealer.


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auto wrecker from a 2.slow mk4/beetle, they re under the engine cover in the engine bay up decently high so they are easy to get and don't have the moisture problems that plague the b5/6/passat b5s. Plus it will be from a vw, the u pull here charges $15 for one.