Empty Blender...

[09mageec]

So for the past few weeks, immediately upon starting the car after it has been sitting a bit, I hear a high pitched, winding noise for about 10-15 seconds each time. It's a sound that I can only describe as an empty blender spinning, hence the title..

I'm thinking my fuel pump, or maybe fuel filter is the culprit. I'm wondering if anyone has experienced this, and if so, how much time to have??

[BMWCurves]

This sound occurs while the car has been turned on with the motor running?

[GotZHP]

Is it a pulley? I just bought a new idler / deflection pulley today. Mine was not that high pitched when it first started to go, but now it screeches. Also when it first started acting up it would only make noise in short bursts

[09mageec]

This sound occurs while the car has been turned on with the motor running?

Yes, immediately after the car turns over, the winding noise starts, goes for about 10-15sec and then shuts off.


Is it a pulley? I just bought a new idler / deflection pulley today. Mine was not that high pitched when it first started to go, but now it screeches. Also when it first started acting up it would only make noise in short bursts

Its definitely not a pulley/belt noise.. this is more of an electric motor/pump noise.

[az3579]

Secondary air pump, perhaps?

[09mageec]

Secondary air pump, perhaps?

BP, that's an interesting idea.. SES light came on about a year ago and the code it threw was for the secondary air pump. But one day it went away and hasn't come back on since. Do you think I could be on its way out without throwing a SES light? Also, have you heard of this sound getting linked to the SAP before?

[az3579]

Never heard of this sound before, but I never searched for it online either since I never had that problem.

[09mageec]

Never heard of this sound before, but I never searched for it online either since I never had that problem.

BP, great call, it was the SAP. Really checked it out today with that in mind. It has always worked, but lately been much noisier than normal, hence the thread.

I guess this noise means the hose that runs from the pump to the check valve starts to deteriorate and crack over time. Gonna give that a look after work..

Thanks!

[BMWCurves]

Nice, let us know how it works out.

As an aside, what does the secondary air pump do? I'm guessing it's involved with the exhaust system. Cursory internet search suggests more complete combustion of exhaust gases in the catalytic converter.

[09mageec]

Nice, let us know how it works out.

As an aside, what does the secondary air pump do? I'm guessing it's involved with the exhaust system. Cursory internet search suggests more complete combustion of exhaust gases in the catalytic converter.

ding* ding* ding*

Yes, you are correct as far as I'm aware.. Literally sounds like someone switches a vacuum on once I turn the motor over... Should have thought a bit more about the title of the thread before starting it, haha.

[zYx]

Nice, let us know how it works out.

As an aside, what does the secondary air pump do? I'm guessing it's involved with the exhaust system. Cursory internet search suggests more complete combustion of exhaust gases in the catalytic converter.
It adds extra air (oxygen) directly into exhaust so catalytic convertors heat up more quickly and reduce pollution during cold start when the engine is running very rich.

[BMWCurves]

It adds extra air (oxygen) directly into exhaust so catalytic convertors heat up more quickly and reduce pollution during cold start when the engine is running very rich.

I've seen that explanation but it confuses me a bit. What is the air source that the secondary air pump uses? If it's exterior air, the air shouldn't be considered "warm" as compared to exhaust gas, right? So how would extra exterior air heat up the catalytic converters any more than having just the exhaust gases pass through the converters?

[zYx]

It uses external air, on my M54B25 it is a bit different than on B30 and it has small washable foam filter under top removable cover.

Like in this video:

http://www.youtube.com/watch?v=HgvtCI21Aio

I think the temperature of air does not matter, exhaust gases burn hotter with added air (it is my amateur physicist opinion).

Edit: there is an explanation in this article:

http://blog.bavauto.com/12072/bmw-secondary-air-system-fault-code-diagnosing-how-to-diy-obd-ii/

[BMWCurves]

^Good info, thanks!

[09mageec]

Yes, thank you.


Sent from my iPhone using Tapatalk

[09mageec]

Ive also recently found out why it's so noisy all of a sudden.... There is a bearing in there that is known for getting dry. This is what is making the noise, however, it is still working properly, just a bit noisier than normal. When the day comes that the pump starts to get fussy I have a real issue, as these pumps are pretty pricy.


Sent from my iPhone using Tapatalk