The secondary air pump is basically composed of a series of plates that are held together by 6 aluminum rivets to make up the body of the actual pump. The rivets tend to break, allowing the plates to separate and leak air. The reason that you only hear it momentairily after startup is because it only runs for about 30 seconds after the car has been started on a cold engine. You can easily fix the problem by first removing the secondary air pump, removing the broken rivets and possibly drilling out the others. Then replace them with machine screws and locknuts. This should eliminate any problems and extinguish your CEL. Depending on how long you've known the noise to be there, you may consider taking the pump apart and cleaning the internals with brake cleaner. It's not absolutely necessary, but just a suggestion. Also, while you're working in that area, you may want to replace the ribbed rubber boot between the MAF and the ASC valve as it's known to crack and give you misfire codes as well as trigger a CEL. Good Luck, sorry I came in so late. |