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Discussion Starter #1
Ok, I can't tell if this is spark knock or timing chain rattling. Everytime I put a load on or WOT you can hear it and it sounds like the timing chain is just real loose. The sound has gotten worse since one of the guys up at the shop advanced the timing cause it was loping real hard. And I dont have a timing mark, so we went by ear.

When you hit a bump you can hear it, WOT you can hear it...when you left off the gas you can't hear it. Only under a load. Breaking hard you can hear it sometimes no.

I know sounds are hard to diagnose via internet but I'll upload a video sometime whenever i can get someone to ride with me.

Any suggestions? When I get time this weekend I'll check the timing chain for slack. But i just dont wanna drop the oil pan and pull the balancer and and **** like that especially with no air.

5,030 Posts
V8 Kid said:
Ok, I can't tell if this is spark knock or timing chain rattling.
EZ- pull a bunch of timing out of it and see if the noise quits!

If it does- timing too advanced initially.

If it doesn't- timing chain might be at fault, but I have to say- it has to be LOOSE (and an OEM-type set-up) to actually hit the inside of the timing cover, IMHO.

If it's the chain, you should be able to get it to do it sitting still, in park, by working the throttle on and off. It's most likely to do it during deceleration.

Be sure the fan's not getting into the shroud, that there's nothing moving around enough to contact any moving part under the hood. I'm definitely thinking it's something besides the timing chain...

1,971 Posts
under load is probably spark knock

how much slop is in the chain when you grab the balancer and yank it back and forth ?

if theres alot of free play in the crank before the chain takes up slack then yeah put a new chain set on

some slack is normal

too much and it will fall off the crank sprocket and put it out of time eventually when it is shut off, some day

you can set the intial timing with a mechanics vacuum guage 15-18 inches of mercury, in the green zone of the guage

try running with the vac advance disconnected, or back off the dizzy some

and then see if it does it still.

only needs to be 4-6 degrees BTDC
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