Any Pontiac guys on here? Need insight.

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I will post the video, the first noise you hear is the door buzzer, it comes on, goes off then, comes back on for a second. Car starts, good a quiet then 2 noises start, the really loud high pitch sound was from the carburator, that has been addressed, the one not so loud and a little lower in pitch is the one in question. Very hard to hear it in this.

 
So this was before you pulled things apart I'm guessing ?
 
Sound not good at all like metal to metal rubbing non stop in consistent manner. Not valve train or crank/rods/pistons that is something spinning rubbing. A mechanic stethoscope could tell you is it front or rear of engine under timing cover ect helps narrow down location.
 
Did you check the Harmonic Balancer?
I'm going back a lot of years. More then 50 to be exact.
I had a similar noise in my 65 Gto.
 
Yar nam dol said:
Did you check the Harmonic Balancer?
I'm going back a lot of years. More then 50 to be exact.
I had a similar noise in my 65 Gto.
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I would think if it was the balancer that, when we were under it with it running it would have been noticeable but, when under it the noise is much quieter
 
I had a Tempest with a 400 in it. The water pump has a stamped sheet metal plate in it. That plate came loose in the one I had and sounded exactly like that. Í know you ran it without belts but the noise I heard in the video is what my Tempest sounded like with that loose plate.
Jerry
 
No, not yet but, I think it may be the next thing if I don't find a smoking gun.
 
If it was the chain you would have heard that while you were under it running. Still at this point its worth the look see.
 
Shenango said:
I had a Tempest with a 400 in it. The water pump has a stamped sheet metal plate in it. That plate came loose in the one I had and sounded exactly like that. Í know you ran it without belts but the noise I heard in the video is what my Tempest sounded like with that loose plate.
Jerry
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I had a 80s Fox Body with a 5.0 the water pump shaft "walked back" and rubbed the metal plate on the back of the water pump. That is a very possible occurrence. id be stethoscoping it and trying to pinpoint.
 

Dartswinger70 said:
I had a 80s Fox Body with a 5.0 the water pump shaft "walked back" and rubbed the metal plate on the back of the water pump. That is a very possible occurrence. id be stethoscoping it and trying to pinpoint.
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I have run the engine with the belts off to eliminate any pulley driven part making the noise.
 
Right not water pump or any belt driven unit. But could be cam rubbing or cam gear rubbing something. Hopefully found corrected without engine damage.
 
340sFastback said:
Right not water pump or any belt driven unit. But could be cam rubbing or cam gear rubbing something. Hopefully found corrected without engine damage.
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I think we are safe right now but, not going to run it again until I'm sure it's fixed.
 
Starter Bendix not disengaging from the flywheel.

Sounds like it at the sudden stop sound at the end of the video.

Those GM starters need to be shimmed out away from the flywheel so things don't bind. He probably did not shim it after building the engine.

Bind, like as in an odd engine noise that nobody can figure out.


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George Jets said:
Starter Bendix not disengaging from the flywheel.

Sounds like it at the sudden stop sound at the end of the video.

Those GM starters need to be shimmed out away from the flywheel so things don't bind. He probably did not shim it after building the engine.

Bind, like as in an odd engine noise that nobody can figure out.


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Checked that...not it.
 
Check Again >

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Post #42. Pic of the oil pump drive shaft. Rough end is quite normal. If you look closely, the last 3/16" of the shaft is smooth...& slightly larger in OD compared to the rough area. The body of the Pontiac dist is a tight fit in the hole, to a depth of about 2.5"; no way it can move around to rub on anything. The gear on the dist shaft is recessed so that the smooth end of the pump drive is a tight fit inside the gear to locate & centre the drive shaft.
 
Another possibility.....worn thrust brg.
Engine thrust brg is on #4 main. Lever back & forth on crank. Normal endplay is 0.008" or less.
More likely to be damaged [ worn ] if used with a T400 trans. Oil pump drive shaft runs veeeery close to a counterweight; could come in contact & make noise if brg is worn.
 
Bewy said:
Another possibility.....worn thrust brg.
Engine thrust brg is on #4 main. Lever back & forth on crank. Normal endplay is 0.008" or less.
More likely to be damaged [ worn ] if used with a T400 trans. Oil pump drive shaft runs veeeery close to a counterweight; could come in contact & make noise if brg is worn.
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I did see where the oil pump drive rod runs super close to the crank wieght. I think they said like .040" clearance between them.
 
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