Any ideas of what could cause a marble sounding noise at 3k? My valvetrain doesn't make a sound anywhere else in the RPM range. The teeth are still perfectly square, all my bolts are tight, and there's no plastic remnants in the pan. Maybe the tensioner?
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may be timing case related? what is a marble noise? -
Could be knock. Sound like bb's rattling around in a glass jar? Is it 3k at full load in a higher gear?Comment
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The little idler sprocket for the timing chain could be on its way out, or maybe the top bolt of the driver's side chain guide rail is stripped.Comment
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Full load = loud pedal floored3k in 5th going down the highway, so yes?
Just cruising wouldn't cause knock.Comment
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You sir need a new chain. I had the same exact issue.
When I compared the new to old I discovered the actual links worn allowing play in all directions. I'm assuming it slapping around as it goes down the guide rail.
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After driving around on some smooth quiet roads (seriously a needle in a haystack down here) I'm hearing definite chain noise below 3k. Time for an engine swap haha!
Between this and the super loud input shaft bearing on the G240, it's time for something bigger.Comment
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I can haz old M42?Comment
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The M42 seems to not run smooth at kinda exactly 3000 RPM.
Just to mention.
With my M42 and many miles on the engine, I could easily hear that 3000RPM just wasnt healthy for it, while 2900 and 3100 are fine again.
Even on a complete rebuild M42 now, since I knew, I can still here the difference at exactly 3000RPM.
If you drive on the highway for a longer distance, I would also avoid 3000RPM, and rather go a bit faster or a bit slower.
But I dont know if its just my engine and others are fine...?Comment
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If you are having bad noises and vibration at 3000rpm, you need to open up the timing covers and inspect things.Comment
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