Paul_G
Well-Known Member
- Local time
- 3:52 AM
- Joined
- Dec 24, 2013
- Messages
- 2,191
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- Location
- Surprise, Arizona
The 318 in a friends 73 Plymouth started making a very odd noise. Sounded like something rubbing along with a bearing going out, both sounds at the same time. Sounded like it was coming from inside the engine. Oil pressure is normal, engine hitting on all eight cylinders. Running normally.
First thing, I took off the belts, noise still there. Still sounds like it is internal. Pulled valve covers, rockers all good, pushrods all good. No soft lifters., Got out the camera and went inside and looked at a few cam lobes, all looked fine.
So what next? Distributor gears, Harmonic balancer? Time to get really old school. I put an ear plug in one ear, got a piece of long rubber hose and put it up to the other ear. Probed around with the open end of the hose to try and narrow it down. Found the noise mostly around the balancer.
Pulled the balancer off and ran the engine, noise gone. I have never had a balncer making a noise like that. Got out an old 360 balancer and put it on for testing purposes, yea it is externally balanced and can not stay on. Started the engine and no noise. So what gives with the other balancer?
There is a dust shield pressed on to the back of the damper. I worked it off of the damper, reinstalled the original damper. Noise still gone. Dont know if the shield was bent somehow, or knocked out of position, or just loose and rattling around. The damper is back on without the shield and running smooth.
First thing, I took off the belts, noise still there. Still sounds like it is internal. Pulled valve covers, rockers all good, pushrods all good. No soft lifters., Got out the camera and went inside and looked at a few cam lobes, all looked fine.
So what next? Distributor gears, Harmonic balancer? Time to get really old school. I put an ear plug in one ear, got a piece of long rubber hose and put it up to the other ear. Probed around with the open end of the hose to try and narrow it down. Found the noise mostly around the balancer.
Pulled the balancer off and ran the engine, noise gone. I have never had a balncer making a noise like that. Got out an old 360 balancer and put it on for testing purposes, yea it is externally balanced and can not stay on. Started the engine and no noise. So what gives with the other balancer?
There is a dust shield pressed on to the back of the damper. I worked it off of the damper, reinstalled the original damper. Noise still gone. Dont know if the shield was bent somehow, or knocked out of position, or just loose and rattling around. The damper is back on without the shield and running smooth.
