Start up noise that goes away when engine warms up

[cmoore1953]

I have a 70 Lemans w a 400ci and4bl carb. When I first start the engine there is a loud shrill noise, hard to explain, that sounds like a bearing about to wear out. If I rev the engine it decreases and after about a 5 minute warm up, the noise dissipates and the car runs fine. It's seems to coming from the front of the engine around the water pump area but it's really difficult pinpointing the culprit. Any help is greatly appreciated. Thanks!

 

[melsg5]

Could be alternator, power steering pump, water pump etc. You need to use a length of rubber hose and hold one end near your ear and the other end move around until you pinpoint the source of the noise.

 

[cmoore1953]

Thanks for the tip. I'll give it a try!

 

[cammerjeff]

To me it sounds like a V-belt slipping until it warms up, how old are the Belts? But as stated it could be a bearing, but most bearing noises do not go away once the engine heats up.

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[cmoore1953]

I just replaced the a/c belt. I'm not sure how old the power steering or alternator belts are. I'll check them to see if they need to be tightened. Thanks for the tip!

 

[melsg5]

drip some water on the belts and see if the noise changes