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bill in denver
Joined: 20 Feb 2011 Posts: 1
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Posted: Sun Feb 20, 2011 11:08 am Post subject: exhaust noise from 1998 328 near engine |
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Hello I have an unusual rhythmic knocking wu-ing noise coming from my wife's 1998 328. The noise comes from exhaust side of the head near the fire wall. It doesnt sound like a exh manifold leak instead it sounds reminds me of EGR valve leak. I know the car has no EGR, I removed the hose for the secondary air, it makes no difference. Do the secondary air injectors have check valves where they insert into the manifold? Any one have this sort noise? I can hear it when the car drives uo the drive way, I thought it was a bad idler bearing for the serp belt, kind of a "wuwuwuwuw" sound, but the noise does not come from the front of the engine.
Any advice is appreciated!
Bill |
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geminiys
Joined: 13 Oct 2004 Posts: 182 Location: SF, California
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Posted: Sun Feb 20, 2011 5:42 pm Post subject: |
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Does the sound go away in about 1 or 2 minutes after a cold start or stays on for the duration of engine running after the trip? If it goes away, the Secondary Air Pump bearing is going south. The only way to get rid of is to replace the Secondary Air Pump. The Air Valve must be replaced too as it is the cause of the pump going bad. Improperly functioning valve causes moisture to accumulate in the pump, directly effecting the bearing. The valve is located in front of the engine still on the exhaust side. It has a black plastic cover on top for the looks, at least mine does. |
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Whitdog
Joined: 15 Nov 2006 Posts: 90 Location: Evansville, IN
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Posted: Mon Feb 28, 2011 12:41 am Post subject: |
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I would check and make sure a spark plug has not gotten loose. Torque them and see if the noise quits. A loose plug will have a funny sound...sort of like a valves ticking but it is actually compression leaking, aka....air. I had a plug loosen up and it drove me nuts until I figured it out.
Whitdog _________________ Indiana Hoosier who likes European rides |
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