Engine noise question, new RT

[Dude]

Just bought an 06 R1200RT and I'm noticing a slight tap or knock from the engine at low rpm when starting out in 1st gear. Sounds a little like wrist pin knock, piston slap, or spark knock, but only does it when blipping the throttle from idle and when taking off from a standstill and immediately goes away as rpms increase. Does not make any noise under hard acceleration once moving which is a little confusing.
Anyone have any ideas? Anyone else hear this on theirs?

[ben1364]

Dude wrote in part, "Just bought an 06 R1200RT and I'm noticing a slight tap or knock from the engine at low rpm when starting out in 1st gear. <snip> ...Anyone have any ideas? Anyone else hear this on theirs?"

Nope. Mine doesn't do it and I have no ideas. I suggest that you drop in to a dealership and have them test ride it. You might want to test ride another RT as well.

[bwalk]

Had same concern with my new 2006. Took it in for the 600 and dealer said normal noise. Now have 4K with no issues 9othet than occasional burning clutch smell )and have just gotten used to the noise

[Ruben]

Just bought an 06 R1200RT and I'm noticing a slight tap or knock from the engine at low rpm when starting out in 1st gear. Sounds a little like wrist pin knock, piston slap, or spark knock, but only does it when blipping the throttle from idle and when taking off from a standstill and immediately goes away as rpms increase. Does not make any noise under hard acceleration once moving which is a little confusing.
Anyone have any ideas? Anyone else hear this on theirs?What are you using for fuel? Premium?

[HAlanJ]

If it sounds like a wrap on an empty can - it is. You're ignoring the electric fuel gauge and a mechanical reminder is telling you to fill up. I have a '06 R12RT and only get this sound when I running on the reserve.

[Nodakgus]

Dude -

I drove home a new 1200RT last December. I also had the same noise issues. My dealer said that the adjustments that are made at the 600 mile service should clear most, if not all, of that up. He was right. It may not have been eliminated but substantially less than before.

I am coming from a Harley Road King (I still have that bike) and I have no doubt that if I had stock pipes on the Harley that I would hear all sorts of noises from that Twin Cam engine!

[emerson]

If you can rule out lubrication-related problems as a cause, the next step would be to remove the valve cover(s) and check valve lash. On older import engines, mechanical lifters require periodic valve lash adjustments (typically every 30,000 miles). Too much space between the tips of the rocker arms and valve stems can make the valvetrain noisy -- and possibly cause accelerated wear of both parts.

To measure (and adjust) valve lash, you need a feeler gauge. The gauge is slid between the tip of the valve stem and rocker arm (or the cam follower or the cam itself on overhead cam engines) when the piston is at top dead center (valve fully closed). Refer to a manual for the specified lash and adjustment procedure. Also, note whether the lash spec is for a hot or cold engine (this makes a big difference!).

On engines with hydraulic lifters, oil pressure pumps up the lifters when the engine is running to maintain zero lash in the valvetrain. This results in quiet operation. So if the rocker arms are clattering, it tells you something is amiss (bad lifter or worn or damaged parts) or the rocker arms need adjusting.

[twilson]

Just bought an 06 R1200RT and I'm noticing a slight tap or knock from the engine at low rpm when starting out in 1st gear. Sounds a little like wrist pin knock, piston slap, or spark knock, but only does it when blipping the throttle from idle and when taking off from a standstill and immediately goes away as rpms increase. Does not make any noise under hard acceleration once moving which is a little confusing.
Anyone have any ideas? Anyone else hear this on theirs?

Low RPM? How low? Without hearing it myself it would be hard to tell. If your TB sync is off a little, I suppose it could be piston slap. Don't know if boxers suffer this but my Goldwing did if one or more of the carbs was out of sync. Otherwise, my RT will "knock" a bit if I lug the engine (I try hard to not do this). Probably would happen regardless of age/mileage.

[deanwoolsey]

Air cooled and in the RTs case air/oil cooled engines normally make some noise. The manufacturing tolerances are looser because of the higher engine temperatures compared to a water cooled engine so there needs to be more room for expansion as the engine heats up. In my opinion small noises are usually nothing to worry about unless they get louder with increased RPMs. I have noticed small intermittent noises in my RT. If you are seriously worried about it drop by a service center and just ask them if it sounds normal.

[Dmilan]

Just bought an 06 R1200RT and I'm noticing a slight tap or knock from the engine at low rpm when starting out in 1st gear. Sounds a little like wrist pin knock, piston slap, or spark knock, but only does it when blipping the throttle from idle and when taking off from a standstill and immediately goes away as rpms increase. Does not make any noise under hard acceleration once moving which is a little confusing.
Anyone have any ideas? Anyone else hear this on theirs?

Dude,

Unless I'm mistaken, Ben in post #2 is being sarcastic. "They all do that".
If I'm wrong, I'm sure he'll let me know.

Anyway,
Sometimes, when taking off in first gear my current RT knocks so loud that I think it's gonna grenade.
I've owned 4 R1200. An '05GS, '08GS, '07RT and my current '05RT
As I recall, to some degree, they all made the noise that you're referring to .
Definitely my 2 RTs. Maybe the bodywork funnels the sound somehow.
Not one of my favorite chacteristics of the machine. I'm just rid'n mine and try'n not to obsess about it.

You can read plenty about final drive issues, and there was the key ring antenna (EWS) failures, front rotor/wheel judder under braking, clunky shifting trans.... etc
But, even with all the boxers out there, I don't recall seeing much regarding catastrophic internal engine failure.

Just read recently on one of these BMW sites of a guy with a similar concern on his RT. Said he rode a demo at the BMWMOA International Rally in TN. That one didn't have the knock. He was perplexed. Wrote that he rides 2-up with his wife. Come to think of it, both of my RTs were purchased used and both had been ridden 2-up. One of them exclusively 2-up for a road trip of 8,000 miles the other owner said "some". Didn't like him. Don't know what that means - some. That's 3 RTs in my small world which all had/have the knock. All ridden 2 -up.... HERE I GO, OBSESSING AGAIN. lol

I don't have the answer. Someone here in this thread mentioned loose tolerances of air/oil cooled design.
Post-up if you learn something about it.

DMilan

[hopz]

Hold on folks... a lot of chat here and a lot of it pretty loose on the facts side.

The BMW does want valve adjustment at 6k intervals and your new to you bike should have had it done. If it has not had it done then either do it yourself or get it done.

Doing a valve adjustment is easy simple and does not require any particularly unusual tools. The bike will take until about 18k miles to fully break in. Until then the valve stems are stretching and getting ready for the long life expected of a great motorcycle. (well into the 100k+ range easy)

As the valves stretch and find their seat in the head, they need adjusting. In the early miles they will make some noise, particularly on start-up. My advice is start the engine (if it is cold)... let warm just a little before driving off. By this I mean 10-15 seconds... say the length of time it takes to put on your gloves.

The chance of it being wrist pins or various slaps or in-fact serious problems are just about nil. I have never heard of it. Valves- Yes, problem- no.

[mneblett]

Hold on folks... a lot of chat here and a lot of it pretty loose on the facts side.
Isn't that standard fare for any Internet tech thread?? ;)

Speaking of which :D --

Until then the valve stems are stretching and getting ready for the long life expected of a great motorcycle. (well into the 100k+ range easy)

As the valves stretch and find their seat in the head, they need adjusting.
That's a new one on me! I believe you'll find that the real source of break-in clearance change is the valve face and the valve seat doing their initial wear/mating to one another. As they become more "intimate" with one another, the valve clearance decreases as the high points on both components wear away and the valve face moves toward the seat. This is what causes the clearance to decrease -- not "stem streching."

[hopz]

Sufficient to say that the entire valve seating process is very true, and according to my information the valve stem stretching is part of it, but the total result is the same. In engines, especially new ones, the valve clearance will diminish.

The diminishing clearance grows less over time to the extent that by the 24k service not much change noted is the norm.

For the new people among us, learning to do your own valve adjustments and the Throttle Body synchronization is fun, saves money and adds another layer of enjoyable involvement in BMW ownership.

Wrench On friends

[mneblett]

Sufficient to say that the entire valve seating process is very true, and according to my information the valve stem stretching is part of it, but the total result is the same. In engines, especially new ones, the valve clearance will diminish.

The diminishing clearance grows less over time to the extent that by the 24k service not much change noted is the norm.

For the new people among us, learning to do your own valve adjustments and the Throttle Body synchronization is fun, saves money and adds another layer of enjoyable involvement in BMW ownership.

Wrench On friends
Hey, Bob -- sorry if my post came across harsh -- not my intent!

And I fully agree with the plusses of learning to DIY!