406 SBC Problem...HELP
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406 SBC Problem...HELP
I have a 406 that has not been run in about 4 years. I got it installed and started it up yesterday. When I started the engine it was making a clunking noise every second or so, after about 30 seconds that went away and she was purring like a kitten. I let it run for 5 minutes and then shut it down. About ten minutes later I started it up again, and there's a new clunking sound like something inside the block banging on the side. Started out happening once a second or so and eventually the frequency increased so that it was pretty much continous. I turned it off after a couple minutes and had to stop for the day.
Where do I go from here? What would you guys do to trouble shoot this?
I did have a small manifold to riser leak when I started it up but that was only for a few seconds until I tigtened the riser bolts a bit.
Mike
Where do I go from here? What would you guys do to trouble shoot this?
I did have a small manifold to riser leak when I started it up but that was only for a few seconds until I tigtened the riser bolts a bit.
Mike
#2
First thing to do is kill cylinders as it's running and see if it stops when you kill a certain one. I have seen a couple of these do this from a collapsed lifter, the pushrod will actually jump out of the lifter pocket and make a clunk noise at it drops back in. If it is a lifter it will not stop when you kill the cylinder.
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OK...so I should run the engine and pull and replace plug wires one at a time and see if the noise stops on a certain cylinder. Is that correct?
I did set the valve lash yesterday before starting the engine if that info helps
I did set the valve lash yesterday before starting the engine if that info helps
#5
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Hey... long time no see folks!
Have you used the old "screwdriver to the palm" trick to take a listen in various places?
My thought is that something is probably sticking. How's the oil pressure look?
Tom
Have you used the old "screwdriver to the palm" trick to take a listen in various places?
My thought is that something is probably sticking. How's the oil pressure look?
Tom
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I don't know the screwdriver to palm trick, but it sounds to me like it's cylinder 6 or 8.
Oil pressure looked good at 65 -70 psi, and I did pull the distributor and spin the oil pump until i got some oil pressure before I started it up.
Oil pressure looked good at 65 -70 psi, and I did pull the distributor and spin the oil pump until i got some oil pressure before I started it up.
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