JohnLP560 Report post Posted October 25, 2010 On my 07 G, I noticed on a cold start, when I turn the key to position 2 there is a really loud fan noise, sounds like it could be coming from the intakes before the engine has even started? It lasts for about 5 seconds and then goes away. My 08 SL did not do that. My 07 has Fabspeed Cat bypass pipes and Fabspeed 70mm X pipe exhaust. I noticed when the exhaust was installed, all the vacuum lines for the stock exhaust was taken out of it. Any ideas whats going on? Quote Share this post Link to post Share on other sites More sharing options...
doltmo Report post Posted October 26, 2010 EGEAR or manual? Quote Share this post Link to post Share on other sites More sharing options...
pockmark Report post Posted October 26, 2010 EGEAR or manual? Quote Share this post Link to post Share on other sites More sharing options...
Swif Report post Posted October 26, 2010 A fan noise sounding like it comes from the intake on a cold start is most likely the secondary air pump running. Quote Share this post Link to post Share on other sites More sharing options...
JohnLP560 Report post Posted October 29, 2010 A fan noise sounding like it comes from the intake on a cold start is most likely the secondary air pump running. Is the secondary air pump related to the vacuum line for the stock exhaust? I have egear and I know what the egear pump sounds like. Definitely not that. Quote Share this post Link to post Share on other sites More sharing options...
kinnsella Report post Posted October 29, 2010 Is the secondary air pump related to the vacuum line for the stock exhaust? I have egear and I know what the egear pump sounds like. Definitely not that. i had a small rock caught in the drivers side air intake, was rubbing against the fan Quote Share this post Link to post Share on other sites More sharing options...
Swif Report post Posted October 29, 2010 Is the secondary air pump related to the vacuum line for the stock exhaust? I have egear and I know what the egear pump sounds like. Definitely not that. Secondary Air has nothing to do with the vacuum lines for the exhuast flap. the air pump is used to help heat cats up for tail pipe emissions. You can also have the pump turn on during a drive cycle if the ECM wants to test the system. If you are hearing the noise loadr then normal you may have the hose going to the air box loose or pinched. Quote Share this post Link to post Share on other sites More sharing options...
JohnLP560 Report post Posted November 3, 2010 Secondary Air has nothing to do with the vacuum lines for the exhuast flap. the air pump is used to help heat cats up for tail pipe emissions. You can also have the pump turn on during a drive cycle if the ECM wants to test the system. If you are hearing the noise loadr then normal you may have the hose going to the air box loose or pinched. Hmm, I have no cats, just test pipes. I had test pipes on my SL, different muffler and it never made that sound. Quote Share this post Link to post Share on other sites More sharing options...
Turbo50Mike Report post Posted November 3, 2010 Hmm, I have no cats, just test pipes. I had test pipes on my SL, different muffler and it never made that sound. The pump doesn't know if you have cats or not...It is just trying to warm them up (if you had them) quickly to reduce emissions. Try to isolate where the noise is coming from. The secondary air pump is located at the bottom of the airbox. There is a plug for it, maybe disconnect it, and see if the noise stops. Quote Share this post Link to post Share on other sites More sharing options...
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