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Discussion Starter #1
My 330ci just threw up a check engine light so I went to check with my code reader (this is a craftsman code reader btw not a BMW specific one) and the code the reader pulled up was P0492 for secondary air flow. I thought okay great it's probably a valve or vacuum line. Awesome. I LOVE working with vacuum lines. :cry:

So I reset the code and let my engine run a bit to see if it came back. I noticed that there was a rattling noise coming from the DISA, so I unplugged the electrical connector to it and sure enough the noise stopped.

So my question is this, regardless I know that the DISA is bad and I will replace it before I drive the car again. But I wanna know, could the DISA be throwing a secondary air code? It seemed off to me. Also could it just be that it's showing me a different code because I'm not using a reader made for BMW? To be honest I'm surprised it pulled a code at all.
 

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It's okay to drive your car with the DISA unplugged for a few days.
 

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The secondary air flow could be related to the secondary air pump.
I'd check the vacuum line that runs above the headers to holes, etc since it can get brittle over time from the heat above the headers.
Also could be a bad check valve, given that the actual air pump is oK.
 

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Discussion Starter #5
Yeah my problem is that it will be a few weeks before I get the cash for a new one. Oh well, I have a car in the meantime. I'll replace it and if the light comes back I'll inspect the secondary air system.
 

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Your P0492 for secondary air flow is likely broken vacuum line from the rear of the intake to the Combi valve on the front passenger side of the engine. Also make sure the large hose on the output of the airpump is not broken/cracked.

Since you have an early 330, then your SAP system is vacuum controlled.

Check the first link below in my signature.
 

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Discussion Starter #7
Alright... if that does happen to be the case then how difficult of a DIY is it and how vital is it? Like should I fix it before I drive the car or can I wait a few days?

Also how many people have heard of dealers charging $338 bucks for a DISA? I've read on other forums of people getting them for $185?
 

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$338 is likely list price.

Its all DIY, READ!
 

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Wow I am an idiot.... I went to check the vacuum line from the air pump to the hard plastic vacuum line running alongside the valve cover.... As soon as I grabbed it with my fingers the vacuum line broke in half. Easy fix, had some vacuum line lying around so I just swapped it out and called it a day. Still gotta do my DISA but at least one of my worries has been fixed.
 

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Your P0492 for secondary air flow is likely broken vacuum line from the rear of the intake to the Combi valve on the front passenger side of the engine..
Wow I am an idiot.... I went to check the vacuum line from the air pump to the hard plastic vacuum line running alongside the valve cover.... As soon as I grabbed it with my fingers the vacuum line broke in half.

Do I hear an echo here??
 

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Unplugging your DISA shouldn't throw codes. I made a 400 mile trip with the DISA unplugged. It threw a code 230 miles into the trip, but I suspect it was a different problem. Order a new one and replace it when it arrives. Or you could do what I did: Pay $7 for some plastic epoxy, take the DISA apart, and use the epoxy to fill the wear area between the DISA flap and the actuator shaft. Search "Critique of the Dorman DISA" for the whole story.
 

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Discussion Starter #15
Thanks for the help everybody. Glad I got the light sorted out here. I'm gonna order a DISA from my dad's buddy who works at the dealer. He gives me dealer price. But does anyone have any insight on the aftermarket one sold on ecstuning?
 
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