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SBC 350 Knock or Tick or?

TJ1978

TJ1978

I have MANY questions
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Ok, when I picked up the 69c10 I noticed a small tick along with an exhaust leak at the manifold. Fixed the exhaust leak but the tick seems to be getting worse every time I start the truck.

I tried using the redneck stethoscope (rubber hose) I thought I located it around the distributor, so reading around I saw others have had this issue before. I thought maybe the spark plug wires were arching causing the sound.

So I put in a spare set of spark plug wires, and nothing same ticking.

The ticking does increase when you give it throttle. I thought maybe cracked flexplate, but I don't see or notice any cracks on it or around the crank flange.

I thought maybe the starter pinion wasn't disengaging the entire way but didn't see anything strange there.

So times it seems louder by the torque converter flywheel but others times equally as loud up top.

I have no oil pressure gauge hooked up. But it seems OK.

I'm at a loss and really trying to not have to pull the engine. I should add this 350 has a murky past. It has sat for 20+ years (but ram when pulled) I checked before installing and it made decent compression.

What else could it be? Some videos from today after spark wire change. I took the dust cover off to see if maybe the flexplate was hitting it.


The third video is of the exhaust leak but if you listen closely you can hear the tick but it is faint because of the leak. It is worse now
 

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So I started the truck and one by one I pulled each plug wire off the distributor, got shocked twice...but I digress.

So when I pulled 3 the sound went away...so I'll pull the cover and check the that out. Hopefully it's just loose
 
I adjusted the valves seems to have gone away.

This begs the question how tight is too tight for lash? Should I go back and loosen it until the sound is gone? I may have gone too tight initially which will smoke the cam. I did back them up a bit but maybe a tad more won't hurt. I did notice that when too tight the engine idle changed or so it seemed.
 

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The cam needs to be at the correct rotation point for each cylinder to adjust.

Much faster if you do not mind a little oil slinging, start the engine. Back them off one at a time, Tighten until the ticking stops, then another 1/4 turn.
 
@ktmoutfront
I had the truck running as I tightenend them down. I'll go at it again and back off make the sound return and then do as you said.

I used this video. Do I need to do as he did and pull the pan and check the bearings?
(He does this at the end)

 
No need to check the bearings unless something else is going on.

One other thing to check is, are the rocker studs coming out of the head? Why were the rockers loose? The studs are pressed in. I had multiple back out on a near new, GM create engine. Had to go to thread in studs.
 
That I don't know. Just a basic "hencho en Mexico" 350 with an unknown-ish past. It came with the C10 and was on a stand, all that was on it was were heads/rockers. But I put a new oil pan, intake, water pump, fuel pump etc on it. It turned over and seems ok, for whatever that's worth.
 
If by tightening down the rocker the sound goes away. Then I shouldn't have to worry about the bearings?

As I've been reading (comments in the video posted above) the reason the sound goes away when the plug wire is disconnected is because there is no explosion forcing the piston down, is this correct?

How do do you know if the bearings are going bad? And at what point will driving it this way cause the engine to break?

I guess I 'm concerned that this may be more than just a loose valve. I posted video with sound but not sure this thread is generating much interest.

Thanks.
 
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