BMW Luxury Touring Community banner

1 - 10 of 10 Posts

·
Registered
Joined
·
187 Posts
Discussion Starter #1
I am hopeful some (maybe alot) here could educate me about valve chatter. I seem to hear what I think is valve chatter between 2500 RPM's and 3000 RPM's. It is kind of annoying, as sometimes I get lazy and let the motor get down in that range rather than downshifting. Perhaps it may not be valve chatter? Any other thoughts? It really only occurs when the clutch is engaged.
 

·
Registered
Joined
·
938 Posts
If you are accelerating hard at 2500 rpms, you may actually be bogging or overtaxing the engine. Several very knowledgable forum members have warned about doing that. That is what I think you are hearing. The K engine has far more torque at above 3K.

I frequently cruise between 2500 and 3000K rpms. But, if I want power, I try to remember to downshift.
 

·
Registered
Joined
·
187 Posts
Discussion Starter #3
I am not sure if that is it, I tend not to accelerate hard under 3500. I do hear it when I acclerate from a dead stop (1st and second). I also cannot hear it when I rev the engine in neuteral, so I would assume the drive train is somehow causing this, but if you read my signature you will see what assumptions get you. :)
 

·
Registered
Joined
·
12,165 Posts
I had a "rattle" about the same RPM you are hearing something, tried replacing the timing chain tensioners (they were just fine), and searched for a while. Finally had to remove the exhaust for something else, discovered the front two flanges were broken off the pipes. Re-welded them, noise went away.
 

·
Registered
Joined
·
187 Posts
Discussion Starter #5
Dave,

I like your suggestion, but I only hear the noise when the drive train is engaged. It seems to me that the noise would occur all the time if it was only the exhaust. Did you hear the noise all the time?
 

·
Registered
Joined
·
12,165 Posts
mowoc said:
Dave,

I like your suggestion, but I only hear the noise when the drive train is engaged. It seems to me that the noise would occur all the time if it was only the exhaust. Did you hear the noise all the time?
It was pretty much anytime at 2500-3500 RPM. Louder when accellerating though.
 

·
Registered
Joined
·
36 Posts
my 06 makes the same noise between 2500 and 3000 at a steady speed.The dealer road th bike and did hear the noise and said they did not know what it was. so I checked the valve clearance and eight of the valves were at there max adjusment .008 in and .0012. I think if they were in the middle of the specs they would be quiter. this winter I will readjust them to see.
 

·
Registered
Joined
·
805 Posts
I suggest you try to identify the system from which the noise comes before trying to diagnose it. This is pretty difficult to do when riding the bike - wind noise, tire noise, traffic noise, even the characteristics of the helmet and the height of the windshield can affect what you are able to hear. Don't assume yet that it only occurs within a certain rpm range or that it only occurs under certain conditions (e.g. clutch engaged). This might be accurate in the final analysis, but all you know right now is that you only hear it on the road within a certain rpm range and with the clutch engaged.

You might try this: put the bike up on the center stand, making sure that it is stable and that the rear wheel is not touching the floor. Remove the left lower fairing. Wait until the engine is dead cold, like you were going to check valves. Get a mechanics stethescope or roll up a piece of cardboard. Have a helper start the bike in neutral, and let it idle at 1000. (Danger: make sure the space is very well ventilated.) Listen all around the valve cover with your "stethescope." See if you can localize and identify the noise. Have your helper rev up to 2000 (still in neutral). Note changes, localization, etc. Have your helper rev up to 3000, still in neutral. And again to 4000. With each trial pay particular attention to the front of the valve cover (not left side forward; front front - closer to the wheel) vs. the left rear of the valve cover. The former is where the timing chain, tensioner, and cam sprockets are located, the latter will resound more to the sound of the valves.

Next, make double sure that the rear tire is off the ground, and do the same set trials with the bike in first. Then do it in second. Then do it in third. By this time you may have gathered useful data, e.g., noise does not appear in neutral at any rpm, occurs when bike is in first, second, and third gear and clutch engaged rpm > 1000. If by this time the noise has not appeared, get a light weight to hold down the rear brake lever, very lightly, so you put a higher degree of load on the drive train. (CAution: the brake pads and rotors will get hot. Do not prolong these trials. If necessary, let the bike and the brakes cool off before continuing.) Run through the trials. If the weight causes too much braking action, replace it with a lighter weight.

If you have not heard the noise by this point, try other hypotheses. Noise at the oil pump? Noise from the exhaust headers? Vibration from fairings, front fender, exhaust sheild? Injector noise? Noise from the gear box? If by this time you have not heard the noise or have not been able to isolate the noise, button up the bike, put in earplugs, and go for a long ride. The noise may not be normal, but it's not going to reveal itself to you today. Good luck.
 

·
Registered
Joined
·
284 Posts
fuel injectors

might actually be ur fuel injectors u are hearing...
call me silly but thats what i think it is on mine.....
versus
valves
 

·
Registered
Joined
·
187 Posts
Discussion Starter #10
Interesting thoughts. I will spend some time with this item this weekend and report back.

I am headed to the CCR later this month, so worse case I will maybe be lucky enough to have some trained ears check it out there.
 
1 - 10 of 10 Posts
Top