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Diagnosing an engine noise.

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Old Oct 4, 2023 | 02:51 PM
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Default Diagnosing an engine noise.

Hey guys. New to the forum and relatively new to Harleys as well.

My wife’s 2004 Heritage TC88 developed a noise I can best describe as something between slapping and rattling. We first discovered it on the ride back from VA to PA. Since I don’t usually ride that bike I can’t tell whether it developed over time or was it instant.

The noise seems to be coming from the front cylinder area. It’s almost non-existent at idle, but gets worse with increasing RPM and slightly worse as the bike warms up.

The bike is all stock to the best of my knowledge with the exception of Screaming Eagle exhaust. 38,000 miles.

So far I had a shop look into the cylinders with a scope and was told they look good. There is some wear on the tensioners but it’s minimal compared to what I have seen reading through some of the posts. The shop also checked the tensioners and compensators and ruled those out.

I have also changed the oil (Regular ol’ 20w50) put in Rocker Lockers and changed lifters to HyLyft Johnson ones. No change whatsoever.

There seems to be no difference in how the bike rides except for that noise. Any ideas on what else I should be checking for?

 
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Old Oct 4, 2023 | 03:21 PM
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This may sound silly, but check the heat shields and clamps. Check clamps when cold and use a piece of soft wood to push on the shield when hot. The clamps can be tight but if the tab welded to the shield breaks on one end, it'll make all kinds of scary sounds.

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Last edited by t150vej; Oct 4, 2023 at 03:22 PM.
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Old Oct 4, 2023 | 03:49 PM
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I’ll check, but to me it sounds like it’s internal.
 
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Old Oct 5, 2023 | 08:23 AM
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Checked all the shields and everything is solid.
 
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Old Oct 5, 2023 | 08:30 AM
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Originally Posted by Grin
Checked all the shields and everything is solid.
Was worth a try, always check the easy stuff first.

Without being there, I wouldn't try to make a guess. Maybe some of the other guys will though. Good luck.
 
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Old Oct 5, 2023 | 08:43 AM
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Could it be the primary chain?
 
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Old Oct 5, 2023 | 07:39 PM
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Does the noise present when motor is cold, i.e., just started or when up to operating temps or both? Does the noise present at any particular RPM? Does the noise present under acceleration and decel, or both? Get an auto stethoscope, cheap at Auto Zone to help isolate the noise.
 
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Old Oct 5, 2023 | 08:01 PM
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The noise is there when cold but very slight. Lot more noticeable at operating temp.

At idle the exhaust almost completely overshadows it so it’s hard to tell. The higher the RPM the louder the noise is. Accelerating hard uphill doesn’t make it any worse than being at the same RPM on a flat road.

Very noticeable at highway speeds (65MPH) in 5th gear.

If I’m doing 65 and squeeze the clutch, RPMs drop and noise goes away.

I tried a very primitive way of using a big screwdriver against random parts of the engine, tranny, primary against my ear and can’t isolate any unusual noises at idle. Tried it both at start up and operating temp.
 
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Old Oct 6, 2023 | 12:04 PM
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Have the cam chain tensioners ever been replaced?
 
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Old Oct 6, 2023 | 12:23 PM
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Not in the 10k miles I’ve owned the bike. They have been checked a few times.
 
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