Re: please help - 03 R6 problems between 4000 and 8000 RPMs
Ok, so we opened the cover up, and the chain was tight, we also double checked that the (new) tensioner was working, which it was. So no problems there. Then we decided to take a new approach. Me and my dad recorded how the engine ran with a video camera, and played it back on the computer, while slowing it down to an eighth of the normal speed. We could see and hear every engine revolution as well as every knock. We did this to see weather we had the highest probability to find the problem by opening up te top or the bottom of the engine.
We opened the top first, and checked the valve clearances (again since the shop checked them less than 1000 miles ago). They were all in spec, except for one was a little tight. By this time, we had taken so much off already that it was maybe another 30 more minutes to open up the bottom aswell. We did, and before we put the oil pan back on, we noticed 2 pieces of metal, about the size of a quarter in the pan.
We decided to take a closer look from the bottom, and noticed that one of the pistons had pieces missing from the bottom of it. Looking at the pieces, they had smooth edges meaning that they had broken off a while ago, probably where the first "tick" came from. However, by manually cranking the engine, we could tell exactly where, and even predict where the knock was. Every 2nd engine revolution or every 4th stroke since there are 2 engine revolutions and 4 strokes per engine cycle.
The reason that we think the piston having parts of the bottom missing, is not causing the knock that we hear, is because, when the knock happens, that piston is not moving at all (we were looking up at it while cranking the engine manually). So, having said all that, it looks like I am going to have to replace the pistons and rings, but also the con rod bearings (the only other thing that makes sense that the knock could be coming from). Since we are going to have the engine out, we are going to reseat the valves aswell. The sad thing is, that wont be able to happen for another 3 weeks since I still have classes.
One thing I am not sure of, is when ordering the con rod sleeves, they have different colors. Is there a way I can check which color to order before we open the engine up, so it wont have to stand open for 2 weeks? I have searched for it, and there seems to be a lot of confusion concerning that topic.