jeez, alot of typo's there eh? first correction, "what's up guys", "how to fix it?" "something very similiar to that"

 

oh yeah, i have a 2000 540i

 

odd

both are unknown codes..what are (if any) the symptoms you're experiencing ?

 

no symptoms, just pulled them codes up when i plugged in the ODBII

 

P0491 & P0492 Secondary Air bank one and bank two.

 

That's a problem with the air pump. Had the same problem on my 99 540iT

Just had to replace the hoses on it.

Tom

 

air polution pump? i can take a look, that might be the problem because i did bump it a few days ago.

 

Yep

 

hey madunix, sorry to bring up such an old post but im hoping you could help me out with an update as to how you fixed your problem. I turned on my car this morning and got a check engine light and the same codes (p0491+2). If your still around any feedback would be greatly appreciated.

Thanks
Vlad

 

Sounds like a secondary air pump problem. The SAP comes on for 60-90 seconds at cold startup to help burn hydrocarbons in the catalyst on a cold start. Usually water in the pump due to a failed check valve. Sometimes can burn out if the relay doesn't shut it down after 90 seconds. Check to see if you SAP fires up (located in front of right front wheel) on a cold start. If it doesn't, then that's your problem. You can run the car without a functioning SPA as it does not affect driveability. It just won't pass an emissions test (clear the codes before an inspection). SOP is to replace the valve whenever you replace the SAP. Kinda pricey repair (SAP ~ $250+ and valve ~ $80)

 

Check to see if you SAP fires up (located in front of right front wheel) on a cold start. If it doesn't, then that's your problem. You can run the car without a functioning SPA as it does not affect driveability. It just won't pass an emissions test (clear the codes before an inspection). QUOTE]

You will most likely NOT pass an emission test if you simply clear the code. These days, most inspecting stations will connect up to your OBDII port and scan for codes, but more importantly, they also scan and check every sensor to ensure it has gone through a suffient number of cycles to ensure it is working correctly. I don't know the specifics, but for the air pump, if it has not been cycled through at least a couple cold starts without failing, then it will state that the air pump status is "pending" and they will tell you to come back after driving a few more days, and they will test again. And of course by then you will have a "check engine" or "service engine soon" light.

 

when i got my car. the air pump was bad. cleared the code, drove for 40 miles. went back and it went through the inspection with no problem.

 

It depends on the locale, but this latest system is rolling out, it has been in Western Washington state for over a year now...sure to be in your location soon!

The Feds are hip to those trying to get around the system, and they are quickly catching up.

 

I had the same problem with my 2003 530i. I ill get a Check Engine Soon Light usually after 2 minutes on a cold start. Do this quick test of removing the hose attached to Air Pump Control valve and have someone start the car for you. If you hear the Pump running and it will have a lot of air coming out of it, then check the Pump Control Valve attached to the fwd right side of engine. In my case, found that vacuum hose attached to Valve was deteriorated, and also had a bad Air Pump Control Valve. I replaced all that and the car has been running fine. I had to reset the code also.

 

I had the same problem

I realize you resurrected an old thread, so I'll be brief:

For anyone finding this thread in a search of Pcodes, you can find what appears to be all Pcodes for all BMWs in this post from RDL.

- All OBDII codes, including BMW-specific P1xxx DTCs specific to the engine computer of each BMW (1) (2)
http://www.bimmerfest.com/forums/showthread.php?t=165198

 

I know this is an old thread but for many of you like myself who finds this post from search engine hope this will help.

I also had this P0491 and p0492 code which is related to the secondary air pump. However, on mine I can still hear the high pitch noise for about a minute during cold starts in the morning so it sounded like the pump was still working. Next I checked the hose from the silver secondary air exhaust valve to the pump. That was good. No cracks. Next I checked the vacuum line connecting to the secondary air exhaust valve. They were hard and brittle and when it tried to pull it off the valve it broke apart. So I replaced all the old and hard vacuum lines all the way back to the engine intake. Reset the codes and it hasn't come back. Turned out to be a cheap fix.

 

locations and part numbers

Old Post, new post - does not matter and in fact good posts, search and review before posting are the key.

SO, I have the same situation as you, and have ran diagnostics with the computer.

Codes P0491 and 2 - hoping it is not carbon clogging the heads...

1. I hear the pump on start up for like the 90 seconds as stating
1a. I also hear a bunch of air noise from under the upper intake manifold in front of the motor

2. Connect diagnostics computer, go into diagnostics, turn pump on - turns on fine, I hear the air noise.

3. Next step is to feel for air out the exhaust = fail

The Y in front of the motor seems fine, but the lines around them seem to be good but maybe hard like you say. SO a couple questions (and I'll do more searching, but this is right on topic):

Q1: "Next I checked the vacuum line connecting to the secondary air exhaust valve." - Where is this?

Q2: "They were hard and brittle and when it tried to pull it off the valve it broke apart." - Was this under the intake manifold? Any pix?

Q3: "So I replaced all the old and hard vacuum lines all the way back to the engine intake. Reset the codes and it hasn't come back. Turned out to be a cheap fix."

Can you post the part numbers and I can then use real OEM to see where they are? thanks a mil.

 

I think the following items are what actually checked out ok as these are the pressure lines from the pump to the valves. From Real OEM:

11727508270 - the hose with the Y that goes under the upper intake manifold

11727553101 - the two valves that are behind the heads that look to be a real PIA to get to!!!

http://www.realoem.com/bmw/showparts.do?model=GN63&mospid=47785&btnr=11_3281&hg=11&fg=50

What were your parts?

 

In your RealOEM link the number 8 valve should have vacuum hose attached to it. It doesn't show in the diagram but there's nipple behind that attaches to a vacuum hose. That's the hose I replaced. My car only has 1 valve but looks like your's has 2 valves so check both hoses. If the vacuum hoses are hard replace it. It's hard to tell if it's leaking but if it's hard it's probably leaking.

I don't have a item number for the vacuum hose. I just keep a few feet around and they work for all my cars. They're about 1/2 inch outside diameter rubber hose you can get at any auto parts store by the foot.

Hope that fixes your problem too.

 

I'd have to take my air intake and air box out get a picture and even then it's tight down there but here's a link to one.
http://www.beisansystems.com/procedures/m62tu_vanos_procedure.htm

scroll down to the picture right above where it says "Remove secondary air blower hose and secondary air vacuum control hose from secondary air exhaust valve".

There you'll see on the right side of the picture where the vacuum hose has been disconnected from the nipple on the valve.

 

Thanks for the fast feedback and link. I remember the valve and vacuum line on my E39 540i, 323ci and 330i I'll have to check again as when I was checking my 7, did not recall the vacuum line (yep, I keep line around, and like the vacuum lines with the braid on the outside...)

With the amount of airflow/noise on mine and where it is coming from - I think (and hope) it is the Y pipe under the intake manifold.

Will report back (even though this is the 5 series E39 Forum - they basically use the same system...