Are you talking about the momentary cam chain rattle at startup?Dirt_Dad said:You people just keep reinforcing the idea that I am not going to do this myself.
Here's a question, while I'm having the tech do the inspection, is that a good time to get the slapping sound (valve chain guide) corrected? Do I need to have them order parts in advance for that?
If so, this is how it was explained to me...........
The hydraulic tensioner needs oil pressure to assist it in applying the proper tension. As a result, there can be some rattling until that pressure is reached.
Add to that, the tensioning mechanism itself has a plunger-piston that has teeth on it that assist it in staying "close" to the desired position. In other words, as wear takes place in the chain and it requires are further "throw" of the tensioner piston, there are times where the plunger will extend past the next tooth. As a result, when the bike is not running and oil pressure is reduced, the plunger does not return as far back into its bore because the most recent tooth now catches and serves as a stop. Think of it like a ratcheting tie down wheel on your boat trailer.
Because of the amount of throw associated with each toothed segment on the plunger, there are times when there is very little difference in plunger position when there is oil pressure and when there isn't. On the other hand, as the wear causes the plunger to extend to the furthest distance just short of the next tooth, the distance between extension under pressure and no pressure is increased. So, sometimes we have less rattle at startup. Some times we have more.
I would be far more concerned if there was a sudden increase in the length of time for the rattle to go away. If it seemed like it was taking too long to oil-up.
I notice if I ride everyday, I get less rattle time. Sometimes none at all. I suspect that just means it takes some time for the tensioner to oil-down.
I remember seeing a diagram somewhere showing the oil paths of the Tenere. The cam chain is at the top and the end of the line. Basically the last place to get pressure.