4500 RPM Knock

[aviscomi]

Having not owned this 2004 R1150 RT very long I'm not sure if this is normal. Around 4500 RPM under load I hear a knocking from the front portion of the engine towards dash. Coming from the V-Twin world, some of these noises are normal. I been running 93 octane gas. Is this normal for a Oilhead?

[roger 04 rt]

No, it's not normal. My bike started doing that just before an in tank hose ruptured, leaving me stranded by the side of the road.

 

I recommend you make a return flow test on the fuel system. Here's how: http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=838585#Post838585

 

The basic idea is that the fuel pump puts out about 110 liters per minute, all the time, when the engine is running. At idle little fuel is used so almost all of it returns to the tank. If the quantity returning is about 2 liters per minute then the pump, hoses and filters are good.

 

Visual inspection often misses even large leaks in the in-tank hoses.

 

There are other possible causes but since you haven't owned the bike long it is a good idea to make the return fuel test.

[aviscomi]

Hmm...the knock only occurs from about 4,440 RPM to 5,000 RPM. If fuel pressure was the issue wouldn't the knock continue all the way through the RPM range?

[roger 04 rt]

Maybe, maybe not. We'd need to look at where the injector pulse widths are the longest for the throttle angle and also the ignition advance is reduced at some higher loads.

 

Half of the reason for my advice is that you've got a new-to-you bike and the in-tank hoses do rupture suddenly. I'd do it if it was mine.

Edited April 1, 2017 by roger 04 rt

[chrisolson]

+1 on Roger's suggestion. It's sound advice and fairly simple to do.

[Tri750]

Many HD riders shift gears way too early when new to BMW's.

What gear are we talking about?

5th is about a 1:1 and 6th is an overdrive .

 

These engines like to rev and complain when you short shift like so many HD riders do.

By under load, if you mean uphill in 6th, yes it will ping.

Try spinning the motor higher .

[aviscomi]

Many HD riders shift gears way too early when new to BMW's.

What gear are we talking about?

5th is about a 1:1 and 6th is an overdrive .

 

These engines like to rev and complain when you short shift like so many HD riders do.

By under load, if you mean uphill in 6th, yes it will ping.

Try spinning the motor higher .

I believe it was 4th gear at about 4500 RPM on level terrain.

[Mike279]

Since this is a new to you bike you should do all the basic maintenance and test things like compression to get a better picture of what you have. My RT suffers from high compression and the AF-XiED helps the knock quite a bit. Mike

[dirtrider]

Having not owned this 2004 R1150 RT very long I'm not sure if this is normal. Around 4500 RPM under load I hear a knocking from the front portion of the engine towards dash. Coming from the V-Twin world, some of these noises are normal. I been running 93 octane gas. Is this normal for a Oilhead?

 

Morning aviscomi

 

I only have a couple of minutes of WiFi this morning so this will be quick.

 

You need to be our eyes & ears on this knocking problem as we can't hear or see the bike.

 

So, can you define the knocking in a LOT more detail-- such as, any idea if it is full engine speed (once per rev), or 1/2 engine speed, or some other order?

 

Is it throttle sensitive with a small change in throttle position (can you play it in & out with just a slight throttle position change?)

 

Is it worse going up hill than on a level road? Is it worse with a passenger/load on the bike?

 

On the BMW 1150 there are many places for a knock(s) to come from, some normal & some not so normal.

 

Remember that you are sitting right on top of that engine with very little sound buffering (open the hood on your car then stick your head under the hood then revv it to 4500 rpm's)

 

If you determine that your problem is a combustion knock then it could be due to what Roger posted above (fueling flow issue)

 

Or could be due to high compression due to your engine burning oil in it's earlier days coking up the inside of the combustion chambers & raising compression (not that uncommon in the BMW boxer)-- (You might want to run a hot engine cranking compression test).

 

Or it could be one or more of all those internal cam chains ratting (again not uncommon)-- The front one comes to mind on a 4000-5000 RPM chain rattle/knock). That one is also VERY difficult to diagnose as pulling the front of engine will show that everything looks normal, (that chain is also oil pressure tensioned)-- That front chain can stretch just enough to contact the engine case at higher RPM's under certain conditions.

 

Or you could have an ignition timing problem (ie someone installed a new HES & didn't correctly time it or it has moved, or ??????)-- Maybe check max ign timing advance--anything under max advance is difficult to read on the 1150 engine as it has dynamic timing control so it dances all over .

 

Or, your bike could have the incorrect CCP in the fuse box-- does you bike have the correct CCP in it?? (this is a good place to start your knock search)

 

Or, depending on the knocking sound & load it could be the starting of a transmission spline issue. The 1150 BMW boxer has an inherent buzz in the 4000-5000 rpm range due to rocking couple & cylinder offset so that can turn a worn spline area into a knocking condition in that rpm range. If you at all suspect this then you might want to remove the starter, zip tie the clutch lever all the way to the hand grip, then reach in with a pointed awl or stiff wire & see how much clutch disk rotational play on the trans input shaft.

 

If the noise is very light & not once per rev then also don't discount the valve area but this is more of a pronounced ticking than a heavier knocking.

 

 

 

[aviscomi]

DR...thanks! The weather is finally nice today here in the Northeast, thus I intend on taking the RT out for an extended ride. I should also note that I have some expertise with V-twins, some of my bikes were featured in magazines (i.e. a SG w/ 120R & Procharger). I remember that when I use to run with the lowers installed on my baggers, noises seemed more prevalent (i.e. cam chains). I only paid $2,500 for the RT, its has a salvaged title. My sole purpose for buying used was to see if I enjoyed the BMW riding experience and if so I would then buy a new BMW RT. The Harley's are just getting to heavy for my 55 year old legs. My Ultra Limited weighed 900+ lbs, a lot of weight for a 5'6" 140lb guy with bad knees...LOL

[roger 04 rt]

Confirming you have the pink coding plug in the electrical box is a good idea and even easier than the return test. Let us know what you find.

[aviscomi]

Confirming you have the pink coding plug in the electrical box is a good idea and even easier than the return test. Let us know what you find.

Electrical box meaning where the fuses & relays are?

[aviscomi]

Confirming you have the pink coding plug in the electrical box is a good idea and even easier than the return test. Let us know what you find.

Electrical box meaning where the fuses & relays are?

Just checked and there is a pinkish colored relay with "TYCO" stamped on the side.

[dirtrider]

Afternoon aviscomi

 

Should be located here--

 

[aviscomi]

Afternoon aviscomi

 

Should be located here--

 

Yes I have that module

[roger 04 rt]

Good, that's the right one. It's a module that connects its pins 30-87-87a and it tells the Motronic ECU that your bike is an R1150RT.