324 olds in a 54 oldsmobile. Just rebuilt and went through everything on this motor. I have started getting this loud click click click (increasing with revs) from the engine but only after it is up to operating temperature. I was terrified that I had a worn cam lobe from improper break in. (Took a while to get her started for the first time). Well today I took the old exhaust hose stethoscope out and it turns out it is coming from the lower half of the combination vacuum fuel pump. I just rebuilt and went through everything on it. Nothing worn- the arm that rides on cam had no signs of wear. Any ideas? I understand if something was worn or loose but why would this change after it warms up?
The engine note changes when the engine is warm, should be noticeable to your ear but many people can't distinguish it. Anyway when the engine is cold it is masking the noise from the pump that you can hear once it is warmed up. I am leaning toward the broken spring theory too by the way. One thing is for sure if you have determined that the noise is coming from the pump you will need to pull it then it will be easy to find the problem.
Yes, the spring is not it the oil. The thicker oil may be keeping it quiet enough you do not notice it. Had a 360 ford with the wrong fuel pump that made noise like a rod bearing when hot. Got it cheap. When the oil thinned with heat you could hear it.
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