Strange Grinding/crunching noise

[Owen]

I bought a Kawasaki 2007 ex500 and have put about 2000km on it since buying it (has 30,000km total). It stared to make a strange grinding/crunching noise.

The noise happens in sync with the revs. If the revs are doing the following:
1-e-and-a-2-e-and-a-3-e-and-a-4-e-and-a-1-e-and-a-2-e-and-a-3-e-and-a-4-e-and-a-
The crunching noise will happen on the 1 and 3 count. As the engine revs get faster, so does the grinding/crunching sound but still on the same 1 & 3 count.
It only happens when I accelerate. Never at idle or when I'm slowing down. The sound is most noticeable when I'm going slowly up hill or when the revs are slowly climbing from 2000rpm. I also notice it in all gears.
Once the engine hits 5000rpm+, I don't really notice it as much. It still happens around 5000 but not as noticeable.
I'm not exactly sure where its coming from either, but I can slightly feel it in my foot pegs.

It does come and go. Today it was doing it, then I went to my Dad's house to see if he might know what it is, then it wasn't doing it any more. Later in the day it was again.

The last thing I did to the bike before it started making noise was change the oil and filter. It didn't start making this noise until 200-300km after the oil change.

Any idea what this could be or what I can do to try and figure it out?

Thanks in advanced!!

 

[Rotten_Ronnie]

Stop running the engine until you get it sorted is my advice. I'm certain others will chime in.

 

[cbcanada]

Sometimes people notice this a bit after is owning the bike. Are you sure the sound wasnt already there? How does the bike run? I would guess its how your motor runs and you are just now getting to know your bike.

I wouldn't be too worried unless there some sort of physical operating problem

 

[Owen]

Stop running the engine until you get it sorted is my advice. I'm certain others will chime in.

I'm definitely trying not to but it's damn hard especially since I don't drive.

Sometimes people notice this a bit after is owning the bike. Are you sure the sound wasnt already there? How does the bike run? I would guess its how your motor runs and you are just now getting to know your bike.

I wouldn't be too worried unless there some sort of physical operating problem

I'm not %100 sure it wasn't there before....BUT it does come and go. Today it was doing it, then I went to my Dad's house to see if he might know what it is, then it wasn't doing it any more. Later in the day it was again. I guess I should add that in the problem description in case that might help someone point me in the right direction.

It seems to run normal, as far as I know. My experience is limited to the 2000km I've put on it in the last 3 weeks haha.

 

[TwistedKestrel]

Crunching noises are usually pretty bad. Usually it's associated with transmission trouble, but if I understand you the sound is happening all the time, even when the bike is not in motion.

The noise happens in sync with the revs. If the revs are doing the following:
1-e-and-a-2-e-and-a-3-e-and-a-4-e-and-a-1-e-and-a-2-e-and-a-3-e-and-a-4-e-and-a-
The crunching noise will happen on the 1 and 3 count.

I'm not sure I understand what you're trying to say here, though

 

[bboySushi]

No he said never when in idle or slowing down.

Could it be something as simple as something wrong with your brake pads sticking to the rotor (bad caliper?)

Your wheels are on tight?

 

[skapan]

Tight spot in the chain? Loose chain or maybe the chain needs lube?

 

[kneedragger88]

Get it looked at. Grinding/crunching/banging/knocking NEVER good and potentially dangerous. Being that you posted it here means that its likely beyond your mechanical knowledge, and damn near impossible to successfully diag by the description.

 

[inreb]

Sometimes people notice this a bit after is owning the bike. Are you sure the sound wasnt already there? How does the bike run? I would guess its how your motor runs and you are just now getting to know your bike.

I wouldn't be too worried unless there some sort of physical operating problem

Get it looked at. Grinding/crunching/banging/knocking NEVER good and potentially dangerous. Being that you posted it here means that its likely beyond your mechanical knowledge, and damn near impossible to successfully diag by the description.

Go this option #2

 

[Owen]

Thanks for all the suggestions and help everyone!!!

Crunching noises are usually pretty bad. Usually it's associated with transmission trouble, but if I understand you the sound is happening all the time, even when the bike is not in motion.


I'm not sure I understand what you're trying to say here, though

It's not happening at idle or while I'm slowing down. It ONLY happens when accelerating.

It's tough to describe the rhythm so I tried to use a "music" time signature analogy. The sound is happening in sync with the revs but not the same frequency.

No he said never when in idle or slowing down.

Could it be something as simple as something wrong with your brake pads sticking to the rotor (bad caliper?)

Your wheels are on tight?

The wheels are on tight.
I just had the safety done 3 weeks ago, so the rotors/calipers SHOULD be fine. The rear on my dads was fixed when we had our bikes checked, so I'd hope they would have noticed mine sticking. I think this sound is very different to a break squeek, plus it would be a lot more frequent at 60 or 80km/h than 30km since the wheel is spinning faster.

Tight spot in the chain? Loose chain or maybe the chain needs lube?

My initial thought was the chain, since the chain would rotate at the same speed at 3000rpm regardless of which gear it's in, correct?

 

[Owen]

Get it looked at. Grinding/crunching/banging/knocking NEVER good and potentially dangerous. Being that you posted it here means that its likely beyond your mechanical knowledge, and damn near impossible to successfully diag by the description.

I'll probably take it in this week and catch a ride to work with a friend until it's sorted out.

 

[GateKeeper]

Drain your oil and check for metal flakes, maybe you can remove the oil pan and see whats in the bottom of it as well.

Did you use a different brand of oil, synthetic instead of regular oil, change in viscosity, is your filter on correctly, friend of mine put his on backwards and had no pressure, good thing he didn't go far.....

.

 

[TwistedKestrel]

It's not happening at idle or while I'm slowing down. It ONLY happens when accelerating.

It's tough to describe the rhythm so I tried to use a "music" time signature analogy. The sound is happening in sync with the revs but not the same frequency.

That could describe a valvetrain noise, but valvetrain noises usually are constant. Your noise is only happening under load. The noise could also be something like a bottom-end problem on a single cylinder. A crunchy valvetrain noise or bottom-end noise would be very bad. I would not run the motor at all if you could help it and get it looked at.

My initial thought was the chain, since the chain would rotate at the same speed at 3000rpm regardless of which gear it's in, correct?

Nope. Chain speed corresponds to road speed, so chain speed at 3000rpm (engine speed) will be different for each gear.

 

[kcalB]

Does it make the noise first thing in the morning when you get going? With the "decent" weather i only just got my cat upto high temps, and have noticed a big diffrence from cold to warm/"hot" engine.

 

[Brian P]

Exhaust leak at the cylinder head ...

 

[Schneller]

I think it could be pinging/knocking, which increases under load.
There's nothing musical about it though.

http://en.wikipedia.org/wiki/Engine_knocking

 

[Owen]

The help is awesome!!

That could describe a valvetrain noise, but valvetrain noises usually are constant. Your noise is only happening under load. The noise could also be something like a bottom-end problem on a single cylinder. A crunchy valvetrain noise or bottom-end noise would be very bad. I would not run the motor at all if you could help it and get it looked at.

If this is generally what a valve train noise sounds like, it's no where near the same.
http://www.youtube.com/watch?v=wxGUv2feovY
The pace is way to fast for that ticking in relation to my noise. My noise would be happening once every 8 ticks. While the noise is happening, it's a longer duration than the length of one of those ticks.

My noise is also intermittent, as in comes and goes.

It doesn't sound like these either:
http://www.youtube.com/watch?v=uC2TE9Tdpc8
http://youtu.be/cd6_jef33NY?t=1m25s

Nope. Chain speed corresponds to road speed, so chain speed at 3000rpm (engine speed) will be different for each gear.

Haha! Wow, yeah, makes sense since the wheel needs to be moved by the chain. No idea what I was thinking. It does sound like it's between my feet and not at the rear though.

So if the noise is tied to the RNP in regards to rhythm, then that should rule out the front sprocket and chain? Wouldn't the speed of the sound climb as the bike went faster if it was the sprocket and chain.

Drain your oil and check for metal flakes, maybe you can remove the oil pan and see whats in the bottom of it as well.

Did you use a different brand of oil, synthetic instead of regular oil, change in viscosity, is your filter on correctly, friend of mine put his on backwards and had no pressure, good thing he didn't go far.....

.

Since I don't know what the previous owner put in it, it was definitely a different brand that I fully drained before the new oil. First oil change I've done after buying it (less than 100km…**** was BLACK). The specs were what was asked for in the manual (SAE 10W 30 with type SJ / JASO etc) but I did spill a bunch and topped it up with a different brand (same viscosity SAE 10W 30 but may have been a different type).

Assuming there are flakes from the grinding, will flakes be visible if I drain jet a bit like a litre or so? The oil still looks pretty new.

Does it make the noise first thing in the morning when you get going? With the "decent" weather i only just got my cat upto high temps, and have noticed a big diffrence from cold to warm/"hot" engine.

I didn't ride to work today (Hamilton to Etobicoke) and instead rode 4km to a friends house to drive in with him. It didn't make the noise when I left (bike was warm by the time I left) but kind of started after a while.
On the way home after work, it was noticeable much sooner. It was also very noticeable going up the escarpment hill. I don't think there's any relation to how warm the engine is. On many occasions I've noticed it both early in a ride and also didn't start until later on.

If I keep the throttle steady and ride and a very steady city speed (60-65km), the sound doesn't seem to ever be noticeable.

 

[Owen]

I think it could be pinging/knocking, which increases under load.
There's nothing musical about it though.

http://en.wikipedia.org/wiki/Engine_knocking

Is pinging/knocking on a 2 cylinder bike going to sound relatively similar as a car? If it does, then I highly doubt my sound is the same thing.

 

[Owen]

Crunching noises are usually pretty bad. Usually it's associated with transmission trouble, but if I understand you the sound is happening all the time, even when the bike is not in motion.



I'm not sure I understand what you're trying to say here, though

It's a lot closer to the sound at the begining of this video than any of the other sounds suggested:
http://www.youtube.com/watch?v=oL9oTDot_lM

When it does happen, it's at the same tempo as the revs but not at the same time.

I shoud take another shot at trying to record it haha...

 

[meme]

A jug of oil is cheap compared to the stuff that I'm thinking about right now. I would drop.the oil and take a look.
And you should take it to a mechanic.