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Loud secondary air pump

30136 Views 65 Replies 12 Participants Last post by  vaboxr
My 97-528 SAP is kind of loud compares to my 02-530.
It's a fast loud thumping sound.
I think the air passage may have been clogged, but then again this maybe normal for 528.
How's every 528 SAP sound in the morning? Thanks for the feed back.
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My previous e39 went through four SAP pumps in 75K!
BMW says thats because there was probably nothing wrong with the SAP in the first place.

At least that's what the TIS says.

It says "Past experience has shown that the failure of the secondary air system is not attributed to a component fault in the secondary air pump but rather to the secondary air check valve not closing/opening or the actuating relay sticking."
fudman, do you think this SAS could be impacted by carbon deposits?
The bmw tis calls that "soiling".

It says "Due to soiling, the electric valve can no longer close mechanically. Consequently, the secondary air check valve is also no longer closed. Hot exhaust gas constantly flows through the secondary air check valve thus damaging it and possibly also the secondary air pump."
I can't find that tis. tsb/bulletins/bulletin_graphic_temp/B110504g.htm

The best I can find is this.

Or this. bmw/BMW_Secondary_Air_System_Failure.pdf

Is Fudmans tis the same as one of those two?
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