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Old 10-21-2009, 12:17 PM   #1
samwise68
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'69 GMC's got a tick.

Yes, I know. Another "whats the sound" question.

Backstory is..I was driving through a hay field after putting the cows back in. Going slow, and hit a rut, ba-BOOM.

Now, there's a very audile tick at low RPMs. not a double tick, or a knock. I've checked through almost everything, and it seems to be coming from the Passenger Side bank. I pulled the valve cover to see if maybe a rocker nut backed off or something, but I'm not sure how tight they *should* be anyway.

So, I'm thinking either an exhaust leak, a piece of dirt got bumped into one of my lifters, or the rocker?

I just replaced my timing chain and gears, and it doesn't sound deep enough to be a rod knock or piston slap...I don't think...

Opinions?

Thanks in advance guys.

-Sam.
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1969 GMC C1500. long fleet.
307. 3 on the tree. 3.07 gears.
Oliver green. Bent and bruised. Daily Driver.

Quote:
Screw patina... it's a beater...Beaters are cool.
my build thread - Project Homebrew:
http://67-72chevytrucks.com/vboard/s...d.php?t=242993
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Old 10-21-2009, 12:24 PM   #2
jrdv
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Re: '69 GMC's got a tick.

My guess would be exhaust leak. Tighten up your manifold bolts and the bolts on the collectors. You also might have cracked your exhaust manifold--they tend to do that.
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Old 10-21-2009, 12:30 PM   #3
samwise68
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Re: '69 GMC's got a tick.

I have headers, so my first through was it wiggled a bit. I can hear it from down below, as well, which leads me to think it's the passenger side collector.

I don't think a sudden jarring like that would effect the internals? There's nothing special about it - just a 307, all stock, with headers.

Thanks for the insight, as soon as it quits raining, I'll check it out. Any more ideas?

-Sam.
__________________
1969 GMC C1500. long fleet.
307. 3 on the tree. 3.07 gears.
Oliver green. Bent and bruised. Daily Driver.

Quote:
Screw patina... it's a beater...Beaters are cool.
my build thread - Project Homebrew:
http://67-72chevytrucks.com/vboard/s...d.php?t=242993
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Old 10-21-2009, 12:50 PM   #4
69GMCLonghorn
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Re: '69 GMC's got a tick.

I'd bet my left... I mean, I'm pretty sure from what you've said that it's exhaust. I had a 307 with headers in my first truck and had 2 different (idiot) mechanics tell me I had a bad lifter. I finally could see the carbon build up around the header after a few days, replaced the gasket, and was done with it.
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Old 10-21-2009, 12:58 PM   #5
samwise68
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Re: '69 GMC's got a tick.

Excellent, I'm definitely going to have to check out my exhaust. Gaskets aren't that bad, so we'll give it a look over and I'll report back with my findings as soon as I figure out whats going on with this ol' girl.

Thanks again guys.

-Sam.
__________________
1969 GMC C1500. long fleet.
307. 3 on the tree. 3.07 gears.
Oliver green. Bent and bruised. Daily Driver.

Quote:
Screw patina... it's a beater...Beaters are cool.
my build thread - Project Homebrew:
http://67-72chevytrucks.com/vboard/s...d.php?t=242993
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Old 10-26-2009, 02:38 PM   #6
samwise68
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Re: '69 GMC's got a tick.

Well, good news. Tightened up my collectors and header bolts. Started it up when it was cold, so I could grab the tubes.

Nothing by the collector, hopped up and checked cylinder 7. Grabbed hold, and voila, felt air. So, I just gotta get a new set of exhaust gaskets and slap 'em in.

Thanks again guys, I really appreciate the extra minds to help figure this one out.

-Sam.
__________________
1969 GMC C1500. long fleet.
307. 3 on the tree. 3.07 gears.
Oliver green. Bent and bruised. Daily Driver.

Quote:
Screw patina... it's a beater...Beaters are cool.
my build thread - Project Homebrew:
http://67-72chevytrucks.com/vboard/s...d.php?t=242993
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Old 10-26-2009, 02:55 PM   #7
69GMCLonghorn
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Re: '69 GMC's got a tick.

Quote:
Originally Posted by samwise68 View Post
Well, good news. Tightened up my collectors and header bolts. Started it up when it was cold, so I could grab the tubes.

Nothing by the collector, hopped up and checked cylinder 7. Grabbed hold, and voila, felt air. So, I just gotta get a new set of exhaust gaskets and slap 'em in.

Thanks again guys, I really appreciate the extra minds to help figure this one out.

-Sam.
That's great to hear! Glad that's all it was.
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