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That code means that your secondary air pump is not supplying sufficient air during operation. Check and make sure that your air pump, hose from pump to valve, and air pump valve are good. The valve sits on the left hand side of the engine, above the exhaust manifold, and under the valve cover. Then make sure you do not have any vacuum leaks between the actuator and the valve.
 

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secondary air pump is not supplying sufficient air during operation
I never had any problems with mine (so I know nothing about it); but this is what other people put in the bestlinks over time on the secondary air system:

- SAP CLOGS or FREEZES (1): the secondary air pump, SAP (1) valve (aka diverter valve) clogs, taking out the SAS (1) (2) (3) (4) (5) (6) (7)
 

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Discussion Starter · #7 ·
I pulled the hose of the valve, and there was what looked like some frozen water on the back of the pipe. The initial fan sound that I would normally here wasn't happen when I started the car. I was wondering if the motor will blow the fuse or relay before it cooks itself due to freeze up.

It sounds like, if I replace the valve which is the common failure, it could resolve the CEL.
 

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Bad news. If your pump didn't fire up on a cold start, it is most likely either the fuse is blown or the pump is dead. Probably the latter if you found water in the hose (I am presuming you are referring to the air hose and not the vacuum hose). The common failure mode is that the valve fails to close (due to age, corrosion, etc.) and allows hot exhaust gas to backflow the air hose after the pump shuts down. In cool weather, the moisture in the exhaust stream condenses on the hose and trickles into the air pump, killing it. The SOP is to replace both the air pump and the valve (to prevent recurrence of the problem). You should also replace the vacuum hose as that typically breaks when detaching it from the valve. A simple 1 hr DIY although the pump is kind of pricey (~$400 now)
 

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Discussion Starter · #9 ·
Based on the posts and the mileage on my car, I suspect they were due for replacement. The valve was $110 and the air pump was $373 so its a big chunk of change. I hope the relay and the fuse referenced are still good.
 

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Discussion Starter · #10 ·
Forgot to mention that when I pulled off both of the hoses from the valve, the one up by the head. there was no vaccum or air coming out of any of them. I replace the small hose there earlier in the year and when I disconnected it there was some air there.
 

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Here's the DIY. There is no torque spec for the valve bolts. I just used a small ratchet wrench (1/4") to tighten it up. You can feel the funky aluminum gasket compress as you torque down. It doesn't require a lot of torque. Remember less is better than too much. This is not a critical seal (there is no vacuum like the intake side). You just need to keep the SAP airflow going into the manifold. And if you don't tighten it enough, you can hear it (as exhaust manifold leakage).

http://bimmer.roadfly.com/bmw/forums/e39/8238717-1.html
 

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Anyone know what the torque spec is for the air valve bolts?
Did you look in the bestlinks for the torque table for all the bolts in the BMW?
 

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Discussion Starter · #16 ·
Replaced the pump and the valve. Did not have to replace the fuse. Checked to see if the pump was blowing lots of air. I just need to clear the codes and see what happens next.

I was wondering how the air valve is open, is that from force of the air?
 

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Replaced the pump and the valve. Did not have to replace the fuse. Checked to see if the pump was blowing lots of air. I just need to clear the codes and see what happens next.

I was wondering how the air valve is open, is that from force of the air?
The air valve opens via a vaccum drawn by the vacuum pump, which is actuated at cold start, when the air pump is actuated. It closes when vacuum is absent to prevent exhaust backflow into the air pump.
 

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Discussion Starter · #18 ·
Are you describing the flow as show in the attached picture in blue. What does that smaller connection do (red question mark). It seemed that air was going into that connection from the small hose.

Cleared the codes and will monitor.
 

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Smaller hose is to supply vacuum to valve to open when vacuum is applied from solenoid which is controlled by pcm, there should not be any air flow through small hose opening from valve if it does than the diverter valve is bad.
 
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