Failed Big End???

[mercutio]

Hi,

Do the following symptoms sound like a failed/weak rod bearing:

- Consistent "knocking" sound at idle, less when cold.
- Knocking diminishes as engine rev's up
- Knocking is louder and settles to original level when throttling off.

Any other possibilities or tests???

Thanks in advance.

M

[Russ Wolfe]

Hate to say it, but that is what it sounds like. That of a cracked crankshaft.
Loose flywheel will make the same sounds all the time, hot or cold.
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Society is like stew. If you don't keep it stirred up, you end up with a lot of scum on the top!--Edward Abbey

Gary: OK. Ima poop.

[familyof3type3]

had same issue ended up being that the fan was off a bit and was hitting the aluminum shroud. Not sure why it made more noise at operating temp but it was less noticeable when cold.
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lookin for a nice early 60's type 3

[FASTBACKDON]

my old motor did the same thing turned out to be a loose fan housing

[chubby53]

I had an engine with a knock so bad I thought it was going to throw a rod on the way home. Started to pull apart the engine and the fan was loose and I could rotate it a quarter inch opposite the crank. I replaced the fan and all was well.