Name that sound: water pump, P/S pump, tensioner?

[YuCrew]

Looking for opinions regarding the source of the "rattling" sounds I have placed here:

http://home.comcast.net/~yucrew/ML_noise.html

1999 ML430 with 120,000 miles. New fan belt (Goodyear Gatorback) and idler pulley (strictly preventive measure) installed 1,000 miles ago.

P/S pump reservoir is full with no signs of leakage. Sound doesn't change if steering wheel turned full one direction and back to the other. No liquid visible from water pump weep hole. Water pump and power steering pump are original. Cannot determine if the sound is water pump, power steering pump, tensioner or A/C cluth. Sound doesn't change when A/C compressor is engaged.

I don't have a stethescope. Any opinions? Wild a_ _ , educated and experienced guesses gladly accepted. Thanks in advance for your comments and assistance.

Jim

[mbdoc]

Has the front crankshaft pulley recall been done?

[YuCrew]

Yes, TWICE. But quite awhile ago.

71,700 miles AND again at 88,300 miles

I'll check it again but would you suspect it's a problem again with less than 40,000 miles on the balancer installed at 88,300 (vehicle now at 120,000)

Thanks DOC.

[YuCrew]

Pulled the belt off and twisted all the pulleys. It's definitely the tensioner.

Thanks to everyone who responded.