Secondary Air Monitor Not Setting

[stevekat]

Had taken care of multiple ODBII codes on my M54 6cyl. I was trying to avoid resetting the system, but my P1083 and P1085 codes would not go away after about 100 miles, though the Check Engine light went out.

After reset, I have no codes after many miles, but the Secondary Air monitor won't set.

I replaced the short vacuum hose to the exhaust manifold vacuum valve, and can hear the air pump running for about 90 seconds when cold, and it sounds pretty good.

1) Can the hard plastic line with its two rubber vacuum lines on each end be replaced with the intake manifold in-situ, or does one have to take off the intake manifold to access the end that attaches to the solenoid?

2) If one blows in the vacuum line at the exhaust manifold valve, should the line be open or closed? (I can blow into it when the engine is hot or cold.) This may indicate a bad hard line or rubber vacuum line at the solenoid end, but I'm not sure.

3) If it is a bad line, can a vacuum line be temporarily run from the intake manifold to the vacuum valve on the exhaust manifold, during cold start-up, to open the flow of air, to set the Secondary Air monitor?

[Clavurion]

At rest state the solenoid active side is open to atmosphere and when activated there is manifold suction. So to reverse way more or less open.

[stevekat]

Thanks. So applying suction to the line and finding it open at rest is not really a diagnostic.

I was just now able to get my Secondary Air Monitor to set by applying suction (vacuum) directly to the Secondary Air Valve on the exhaust manifold when starting the car from cold.

I could have a bad vacuum line, or bad solenoid, or maybe a bad check valve.

The newer M54's, from about 2004 on, have eliminated the vacuum port on the Secondary Air Valve. I am now wondering if we can retrofit the newer valve, that seems to be activated by the positive pressure of the air pump, and block off the vacuum from the manifold, (but leave the solenoid in place.) Wonderiing if the air hose to the pump shall connect the same, and be in the proper position. I think I am going to start a separate thread on this.