Stock 318 with a new noise.

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Chris Nicholson

Chris Nicholson

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Nashville, TN
Got my '74 out for a little cruise in the country and heard a new noise. This happens under pretty much any acceleration, or even cruising under throttle. Belts are snug, the fan doesn't appear to be hitting anything, and fluids are topped. Seems to be coming from the front of the engine, but can't determine exactly where. Does anyone recognize the noise?

 
Sorry, it's still uploading. Country wi-fi.

Anyway, I removed the power steering belt and the noise went away. Now to figure out if it's the power steering pump or the water pump.
 
The water pump will squeal before it spits the bearings...can u feel anything spinning by hand now that the belt is off?
 
doug 371 said:
The water pump will squeal before it spits the bearings...can u feel anything spinning by hand now that the belt is off?
Click to expand...
Couldn't feel anything, no. Tried putting one end of a broom handle to it (and the power steering pump) and the other to my ear while Dad revved it, but couldn't isolate it.
 
Canceled my plans for the afternoon and started the process of elimination. Started with shining a drop light on the fan while revving, couldn't see it hitting anywhere. Took the shroud off and checked to be sure. Fan blades are nice and tight. There was no noise from the power steering pump when turning, so I'm thinking it's the water pump. Which is going to be fun on this A/C car. :eek:
 
kinda sounds like the pully on the power steering pump is slipping on the shaft (its only a press fit ) or the water pump impeller inside the pump// happens when everything is being driven/under torque
 
It sounds exactly like a water pump impeller that has slipped backwards and is eating the timing cover. Eating it as in I believe I can hear the individual blades scraping away at the aluminum.
 
Just for ***** and grins, turn the AC on and see if the noise is gone... or check your gap on the AC clutch pulley.
 
TURN IT OFF!!! TURN IT OFF!!! Yeah, you definitely don't want to run it anymore like that!:welcome:
 
jazak5 said:
kinda sounds like the pully on the power steering pump is slipping on the shaft (its only a press fit ) or the water pump impeller inside the pump// happens when everything is being driven/under torque
Click to expand...
That's a good idea, so I checked the pulley. Barely wiggles. Doesn't make any noise when steering.

 
while u r @ it go with a kool flow water pump and be done with it
 
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Remove the fan belts & run the engine for a few seconds...
 
If you have a thermal clutch fan, check that clutch too. A bad clutch will allow the fan to wobble, might make a similar noise, and take out the water pump too. Years ago my cousin replaced the water pump on his 350 chevy work van twice before he figured out that the fan clutch was the culprit. Well, he didn't exactly figure it out. Autozone was replacing the water pump under their warranty. The parts clerk there said, "I'll bet you have a bad fan causing this". he was correct.
 
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Got the water pump off today.

originalwaterpump.jpg
 
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