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Old 12-27-2002, 01:55 AM
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Red face Low knocking 350 chevy?

I have a 66 chevy 1/2 ton pick up with a high performance 350 motor. When I first got it it had a little knocking sound coming from the valve covers so I thought Valuve adjustment right? O.K. so I adjust them, but the knocking gets worse, even so much that It's a churping sound now, eventually a low knock at highter speeds. so i park the truck until I can get help from a friend. My friend and I backed off the valves and notice the churping sound got less. so We think scored cam, right? wrong, we replaced the cam and readjusted the valves, only to find out the lower noise is even worse. I have no oil presssue, and I can barely drive the truck 30 mph with out it sounding like the crankshaft is going to fall out of the truck. I had to leave town before I could really get into her. But I'm heading back to town this weekend to try and figure out what's going on with it and sell the truck. I was going to start at the oil pump, then pull the pan t see if I find the problem with out having to pull the motor. I plan to check rod bearings, pistons etc. What do you think it could be? Keep in mind I've aready repalced the cam and lifters, inspected and replaced the push rods, and inspected the timing chain. I realy could use help with this one.

Thanks,
Knocked around. <img src="graemlins/pain.gif" border="0" alt="[pain]" /> :p :p <img src="graemlins/pain.gif" border="0" alt="[pain]" /> <img src="graemlins/pain.gif" border="0" alt="[pain]" /> <img src="graemlins/pain.gif" border="0" alt="[pain]" />

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Old 12-27-2002, 05:23 AM
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Red face

The lack of oil pressure makes me think bearing problem. Possible vave guide but the oil pressure points the other way. When you pull the pan and check rods and mains It will show.
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Old 12-27-2002, 05:37 AM
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You were driving it with NO! oil presure, You now have a bunch of junk from the heads down!
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Old 12-27-2002, 12:08 PM
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The chirping sound was the rockers not having any oil to them. I would have to agree with Roy on this one.
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Old 12-27-2002, 12:17 PM
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Question

[quote]Originally posted by roys63:
<strong>You were driving it with NO! oil presure, You now have a bunch of junk from the heads down!</strong><hr></blockquote>

Yep. Did that ONCE. I was young. Still no excuse. The engine only lasted a few miles.

How far did you drive without oil pressure?
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Old 12-27-2002, 06:33 PM
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Correction, I had alittle oil pressure, more when I added a quart of 30 wieght, however I drove it about 5 miles not taking it over 30 mph. So your think bearings hu?, what would be what to look for when I pull the pan?
To give ya an idea of what could of happened, I did drive it hard a couple of times. If they are main bearings and not just crank bearings will I have to pull the motor and take it to a shop to have them pressed out?
To just pull the pan, on a 2 wd 1/2 ton will I have to pull the motor? I didn't have to with my 70 chevy 4X4.

Thanks for the info. guys
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Old 12-27-2002, 07:24 PM
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you probably had a spun rod bearing, this would let the piston hit the head and sound high up, a spun rod will squeak also, now sounds like you have a few more problems none inexpensive.
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