Buzzing noise on deceleration only if A/C is OFF.

2001 MAZDA MPV
112,000 MILES • 2.5L • V6 • 2WD • AUTOMATIC
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JCANTERGIANI
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2001 Mazda MPV 2.5 V6 automatic with 112K miles. When parked, I notice the engine makes a buzzing noise on deceleration only if the A/C is off. So, if I rev it up and then let it go down, it buzzes for a few seconds. If the A/C is turned on and is cycling, the noise doesn't happen. If the A/C cycles off, the noise comes back on deceleration only. The buzzing noise does not sound like it's coming from the compressor, rather near the top front of the engine in the general area of the timing belt cover.

Thank you for any ideas you may offer.
Jan 14, 2016 at 10:54 AM
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HMAC300
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check to see if belt hits cover then check belt and tensioner for wear recommended replacement of belt and tensioner is 60,000 unless in California where it is 90,000
Jan 14, 2016 at 12:06 PM
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JCANTERGIANI
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Thanks for responding. I just realized that this Mazda MPV 2.5 V6 has a timing chain (not a belt), unlike the Mazda 626 2.5 V6 which has a belt. The buzzing noise sounds like it's from the general area of that top sprocket area, which I think is power steering, Here is a YouTube video of someone's MPV which has the exact same noise on deceleration. Do you think the power steering pump can make this noise when the A/C is off and not make the noise when the A/C is on?
Jan 14, 2016 at 1:49 PM
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JCANTERGIANI
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Forgot to include the link: http://www.youtube.com/watch?v=lF0Fq0CAoT8#
Jan 14, 2016 at 1:54 PM
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HMAC300
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as I really can't pinpoint it I still have to go with the belt, not the timing chain but belt for accessories and tensioner
Jan 14, 2016 at 3:35 PM
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JCANTERGIANI
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Thank you, I really appreciate your responses.
Jan 14, 2016 at 8:19 PM