Engine Noise

[fastlarry]

I have a 2016 RT with just under 13K on it. Will take it in next week for its 12K service. There is a noise emanating from the engine, it seems, that is prevalent when the engine is thoroughly warmed up, but not at all when the engine is first started cold. It sounds like a valve operating with too much clearance, a tap-tap-tap. One opinion was voiced that it is a fuel injector. Any experience out there? These engines aren't given to losing their valve clearance from what I've read. The bike runs just fine.

 

Larry

[dirtrider]

Morning Larry

 

Lots of possibilities on this & without hearing what you have no way of really knowing what you have.

 

Fuel injectors are a bit noisy but are about the same cold as hot & usually can't be heard while riding or with a helmet on/or ear plugs in.

 

On the 1200RT W/C engines the cam driven gears are a selective fit so if a bit too lose will rattle on a hot engine at lower RPM's. (usually goes right away at higher RPM's or higher bike speeds) -- The cam gear backlash is a pain to measure--

 

Could also be valve clearance (is your noise once per crankshaft revolution or 1/2 engine speed??? (this can point to or away from valve clearance noise)

 

Could be internal chain noise also (difficult to track this one down)

 

Might even be a normal noise as you are sitting right on top of a mechanical device with LOTS of moving parts & 2 very large pistons that come to complete stop & then restart twice each revolution.

 

My suggestion is to have your selling dealer's tec take a good look/listen to it as most tecs have experience with engine noises. At least get it looked at by a BMW tec & written up so if you have issues in later life you have an (in warranty) service complaint to fall back on.

 

 

[fastlarry]

At highway speeds I don't hear it or notice it at all. Mostly at idle and putting around town at lower RPM's- and only with a warmed up engine. What is gear driven on this engine? I know the counterbalance shaft is and the power takeoff to the clutch/gearbox. Are the cams driven off the crankshaft or off an auxiliary drive? And, thanks for your input.

 

Larry

Edited September 7, 2016 by fastlarry

[dirtrider]

Afternoon Larry

 

Cam chains drive an intermediate shaft at each cyl head then that intermediate shaft drives both cams on each cyl head using gears (selective fit gears)/

 

Edited September 7, 2016 by dirtrider

[fastlarry]

Definitely something to check, especially if the valve clearances are in spec. Sound, to me, is 1/2 crankshaft speed. It might indeed be normal, but it only manifests itself with a hot engine. Cold, all one hears is the rustle of the valves from that area. Getting stuck in traffic and engine temp rising it is even more pronounced.

Larry

[dirtrider]

Afternoon Larry

 

If it is definitely 1/2 engine speed that sort of points to the valve train area (either valve clearances or cam gears)

 

Not 100% as each side only fires every other piston up but usually 1/2 engine speed points to valve train related.

[gordiet]

That's why I wear ear plugs. GT

[PadG]

That's why I wear ear plugs. GT

Well said! I kept reading all these threads about engine and other noise but have never heard any of them myself, considering the fact that the earplugs goes in, then the helmet, before I even switch the bike on, let alone start it!

[fastlarry]

Bike is being given its 12K service. Valve clearances were all in the middle of their spec range. Not so simple! Going to check some other things; has a 2014 GS with the same complaint from its owner. We'll see what they come up with.

[fastlarry]

Well, the dealer finished their investigation and found nothing out of spec and, not saying " they all sound that way", said it is a characteristic sound from "some" of these wethead engines. I'll let it go; the engine runs great. Wear earplugs more.

 

Larry

[DMilan]

Hello Larry,

 

This looks like an almost all Ohio thread.

 

Unfortunately, the LC engine is mechanically quite noisy.

That's the way it is.

You dealer says "some" of them are noisy huh? I think it's more that "some" folks can deal with/accept it more than others.

 

Good for you for being able to let it go.

As a former owner of 2 LC,an RT and a GS..I found them to have a number of unpleasant and intrusive characteristic noises. I was hoping for a quieter and more relaxed riding experience. I do wear earplugs...didn't cut it for me, sold the bikes. Yes, believe it or not, for me, the noisy nature of the bikes too often, ruined the ride.

 

Some folks don't notice anything unusual, or aren't put off by it..

Some cope with it or otherwise don't obsess about it and focus on the positive aspects of the overall design.

Some get angry at the mere mention of it.

 

I've owned and enjoyed many BMWs (more than my signature lists) and have no axe to grind.

Chimed in on a couple of these threads but didn't start any of them.

 

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=968139#Post968139

 

http://advrider.com/index.php?threads/any-update-on-the-bucket-of-bolt-noise.1157756/

 

http://www.r1200gs.info/forum/2-general-chatter/25817-2016-r1200gs-noisy-engine.html

 

 

Edited October 2, 2016 by DMilan

[NoelCP]

Engine noise is truly my only objection to RTLC. I use 29dB NNR rated plugs inserted so well I have to use blunt forceps to take them out quite often, and w/ those the engine noise really disappears. Still though, it is an odd wart on an otherwise wonderful machine. But it truly is just noise--not vibration felt thru the bike. Of these two sometimes related issues, I'd much rather have noise I can blot out and friendly vibes the the reverse. My F800GT was a vibey machine up over 4200rpm. My '16 RT will go only when someone comes up w/ truly, RT-Lite, meaning full performance/tech/comfort inc electric screen, in a smooth quad or triple w/ a curb weight of around 525 lbs, and HP around 110. I actually DO like the character of the water boxer as far as exhaust note and even engine noise once attenuated w/ properly placed plugs.

Edited October 5, 2016 by NoelCP

[fastlarry]

The tech said the exhaust valves were right in the middle of the spec and could be set tighter. The shims come in .01 mm increments, so I guess one could go almost five increments thicker and go for the min side of the spec. Wonder what effect that would have?

 

Larry

[dirtrider]

The tech said the exhaust valves were right in the middle of the spec and could be set tighter. The shims come in .01 mm increments, so I guess one could go almost five increments thicker and go for the min side of the spec. Wonder what effect that would have?

 

Afternoon Larry

 

It would have absolutely no effect on the way the engine runs, little to no effect on the engine noise, & probably make the next valve adjustment come earlier (note: not valve check but actual adjustment)

 

The exhaust valves usually recede (ie close up lash) way easier than the intakes so I usually set the exhaust to the high side of specs & set the intakes to middle of the spec range.