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clang clang 350

Hi group,

1980 Chevy Sportvan with V8 350 engine.

Yesterday when I was driving to work a clang started to develop. It started as a faint rattle and gradually developped in a loud CLANG. I did some research today and the clang only seems to happen when the engine is running. Starting it with no spark or fuel gives no clang. The sound seems to come from within the engine, I pulled the rocker arm covers and the rocker arms and valve springs look okay to me. When running the engine with the covers off I can hear the sound come from within the engine. I would describe it as a muffled bang like when you hit some metal with a hammer. When the engine idles its not clanging all the time but when revving it does. Looking at the rockerarms it looks like the clang is coming every 2nd revolution. This week I wil do some more, starting with removing the intake manifold since it seems to come from underneath it. In the meantime, does anyone have a clue as where else to look and what it might be?

Cheers,

Timo

Reply to
Timo Wildschut
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I lost a roller bearing when the engine started to sound like what you are describing. The shavings got into the crankshaft bushings and scarred everything. I dropped a new motor in from GM. Start your research online now for the cost of motors(in the $2k range) Bob

Reply to
Bob Truck

Sounds more like a rod bearing to me. Is or was the engine oil low and how does it look and smell?

Reply to
SnoMan

Reply to
Bob Truck

I guess you mean a piston connecting rod and not the valve pushrods? Engine oil has always been at good level and nice and clear.

Reply to
Timo Wildschut

If I were you, the first thing I'd check is the flexplate. A cracked flexplate can give you all sorts of interesting noises that appear to be something other then what it is.

Ian

Reply to
shiden_kai

clang.

Good tip, if nothing is found drain the oil and look for metal particles in and and smell it too. If you spun a bearing it will smell funny (kinda sewer/sulpher like)

Reply to
SnoMan

Check the harmonic balancer for sepration also. Since when you spin it w/o spark you are not reaching rpm , this one would not be found. Look at it while "running" for extreme movement. Or grab it and try and move it if it moves, replace.

Reply to
Kenner Costen

Hopefully They turn off the ENGINE FIRST

if it

Reply to
no one

Turn the motor off first!!!!!!!

Reply to
KENG

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