secondary air pump low flow???

I have a secondary air pump low flow in a 2001 325i.
The secondary air pump works the motor is not seized and i checked the hoses no leaks.
Any idea?


Any help would be greatly appreceated.

TIA

anyone

Ive never had this happen on my e46 but In my co worker's merc its a pump that goes out..the one that helps to warm up the catalytic converters.

Originally Posted by MachRc

Ive never had this happen on my e46 but In my co worker's merc its a pump that goes out..the one that helps to warm up the catalytic converters.

Thanks this is not on my car this is on a friends car, and i checked the secondary air pump i applied power to it manually and it works.
Is there another pump?

Check this link:

http://www.bavauto.com/newsletter/20...ter.pdf#page=6

Did you check the thin vacuum hose between the check valve and the vacuum control switch? I got the same error code (P1418) and isolated the problem to that hose.

Pour Seafoam into the air hose from air pump to engine port before the engine is first started in the morning. The hose will hold just over an ounce of Seafoam. Reconnect the hose and run the car 5 seconds so the air pump blows the Seafoam into the exhaust port. Repeat this fill and restart 3 more times only running the engine 5 seconds so the secondary air pump runs. Then let the engine sit 15 minutes and warm up the car. There will be significant amounts of Seafoam carbon burnoff in the form of white smoke. The carbon burnoff will clean exhaust areas in the path to the O2 sensors that measure secondary air flow.

Originally Posted by refimail

Did you check the thin vacuum hose between the check valve and the vacuum control switch? I got the same error code (P1418) and isolated the problem to that hose.

+1
That is what caused my code.

Originally Posted by ixtoxi

Check this link:

http://www.bavauto.com/newsletter/20...ter.pdf#page=6

Originally Posted by refimail

Did you check the thin vacuum hose between the check valve and the vacuum control switch? I got the same error code (P1418) and isolated the problem to that hose.

Both very helpful thank you.

Well see i did check the hose it does indeed have cracking.
However i look at my car and my hose has the same amount of cracks one is a 2.5l and mine is a 2.8l now i dont think that would affect it.

I will follow the bavauto guide and get back to your guys.


Thank you for you help.

Originally Posted by kamaqazi

Both very helpful thank you.

Well see i did check the hose it does indeed have cracking.
However i look at my car and my hose has the same amount of cracks one is a 2.5l and mine is a 2.8l now i dont think that would affect it.

I will follow the bavauto guide and get back to your guys.


Thank you for you help.

Cracks on any hoses are a sign that they need replacing. If your cars are over 5-6 years old and your hoses have never been replaced, I'd recommend changing them.

Are you throwing any codes? I had a secondary air pump error (sorry, don't remember the error code) and it turned out to be my sec. air pump valve that was the problem. Hoses and actual pump were fine. Just a thought.

Mine throws the same codes when it is cold. I inspected the hose and it is good. Bought a cheap code reader/reset for about 30 bucks. I also squeezed the hose a bit. I plan on replacing it this winter. That code is really no issue though. Part of the emissions system and no big deal. Another thing to look at though is the sec air pump could be going bad. They are not cheap. If you go the SeaFoam route, like I did, do it right before you change your oil and have some time to blow all the crud out through the exhaust. Just my 2 cents.

EDIT: also check the clamps on the hose to make sure they are tight.

A common failure is with the pumps themselves. Inspect the pump very thoroughly. You wana look at the rivets holding the pump case/housing together. Over time, the rivets will break and if you look closely, you'll notice the pump case splitting apart at the seems. If it turns out to be the issue and the case has not split/seperated very much, you can use small nuts and long skinny bolts to tighten the pump case/housing back together, so to say. This will typically cause erratic sec. air flow faults since some of the air flow leaks out of the pump case..............

The code will not let the vehicle pass emissions so i am trying to get this sorted out.

The pumpp is working i have tested it and it looks fine no problems with it at all but i will continue to check it today and let you guys know my fionding.

Thanks for all your help

So i followed the steps in the bavauto article, the check vavle is bad it will not allow air in or out.

So i ordered one form bmw and we will see how it goes.

Again thank you all for your help.

How much it cost to you?

116 for the check valve

I saw them at oembimmerparts.com for $101.

http://www.oembimmerparts.com/catalo...40/5263697.htm

didnt feel like waiting for it in the mail.
and i bought it through work so i beleive it was 103.28

I tried to unhook the pressure air pipe from the secondary air pump. I loosened the meal clamp, but the pipe would not move after being pressurized on to the pump for so long! Any tip on getting the pipe off the pump to check air flow?