Engine Knocking noise at idle , video inside

[piresito]

Hi!
My GS500 started making a weird engine knocking sound around six months ago. Recently adjusted valves, carbs, oil and filter change but the engine knocking continues at idle.

   
• It knocks every two seconds (estimate)
• There is no noise when cold, nor when hot, kinda in between, I think.
• It just does this noise at idle, if I give it throttle, even just a little bit, it disapears.
• On each knock, seems like it "crumbles" the idle

Each time I get a camera to shoot my bike making that noise, it disapears, so I will borrow a video of a GS500 doing exactly the same noise:

In the video the noise happens at 2, 5 , 13, 15, 30 and 37 secs being the best audible "knock" at 5 seconds.


Video link corrected: http://youtu.be/hl5byiFCNwk



Can someone please help me? How can I diagnose it?
My bike is finally running great apart from this noise, thanks to the help of you guys. Can you point me a direction on this one?

Regards,

[gsJack]

•It knocks every two seconds (estimate)
•There is no noise when cold, nor when hot, kinda in between, I think.
•It just does this noise at idle, if I give it throttle, even just a little bit, it disapears.
•On each knock, seems like it "crumbles" the idle

Sounds like the infamous GS500 camshaft knock.  Both my 97 and 02 GSs had it at one time or another.  One of your camshafts has too much sideplay and is drifting back and forth (sideways) at idle causing the knock.  When idle is picked up to a fast idle the centrifugal force of the camchain tightens it all up and it stays inline.  Heavier oil will damp it out, I don't think I've heard it since I changed from 10W-40 oils to the 15W-40 heavy duty truck oils 7-8 years and 70-80k miles ago.  It's really harmless if you choose to ignore it.  Suzuki finally acknowledged it around 2005 I think it was and fixed bikes still on waranty.  Expensive fix with new camshafts and some washers with wavy spring washers between them to keep camshaft from drifting.

You can pull the valve cover and check the camshaft sideplay if you want too.  I found one to be a lot more than the other and more than specs called for when I checked mine and I no longer worried about when I knew what it was but it was nice not having it when it finally went awey.   

[mike10]

I bought my GS500F in 2005 New. I heard that same noise. I took it back to the dealer they told me it was a knock built in from the factory all 500's did it and there was no fix, due to nothing really being wrong. I agree with gsjack its the cam walking thing. Some of the older GS1000, 1100s make the same noise. I just live with mine still runs great.

[adidasguy]

Parts lists show the cam changed in 2004 with the addition of the wavy springy washer at one end.
I saw in the Suzuki manual it is backward compatible if you change the cam. They say older part is not forward compatible - probably because it would introduce the cam noise.

2005 should not be doing the cam noise unless the motor is 2001 or 2002.

[Paulcet]

LOL, sometimes it seems so loud that I'm afraid some well-meaning passerby is going to tell me the motor is going to come apart.  It's probably not that loud, just my imagination.

[Twisted]

  Heavier oil will damp it out, I don't think I've heard it since I changed from 10W-40 oils to the 15W-40 heavy duty truck oils 7-8 years and 70-80k miles ago. 

Funny you say that as mine becomes worse the heavier the oil I use. Mine likes the 10w-40 and hardly makes a noise except on really hot days.

[Unsane]

Cant view your video for some reason...

Does this help?

http://gstwins.com/gsboard/index.php?topic=58760.msg668120#msg668120

[Bullfrog]

Cant view your video for some reason...

Link is broken. Try this one: http://www.youtube.com/watch?v=hl5byiFCNwk

[Dresnewtoy]

I have that knocking sound too, especially when the engine is cold and idling. It sounds like something is rolling around in there. Gives me an uneasy feeling, like the engine could crap out at any moment. Good to hear it's not terminal.

[rayshon]

I sometimes hear a slight "ping" noise when I'm at idle, but that's only for a little while. Doesn't bother me at all.

[Kijona]

http://www.youtube.com/watch?v=gbfKrAm_tMw&feature=youtu.be

That's my bike. You can hear mine makes a very similar sound - especially at :20 when I shut the choke off. Does yours sound like that?

[mike10]

Parts lists show the cam changed in 2004 with the addition of the wavy springy washer at one end.
I saw in the Suzuki manual it is backward compatible if you change the cam. They say older part is not forward compatible - probably because it would introduce the cam noise.

2005 should not be doing the cam noise unless the motor is 2001 or 2002.

My cams have no wavy spring, I guess they forgot to up date mine!

[piresito]

Thanks people!
Kind of a relief...sometimes when I'm at traffic lights the noise is so loud that people may well think that my motorcycle has a midget inside, like Paulcet said...
I had 15W40 mineral oil in it, now changed to Motul 5100 10W40, maybe for the next time I switch to a 15W40 truck oil...anyone knows a brand in Europe that sells that kind of Heavy Duty Oil?
BTW, my bike is a 1997 one...

GsJack, about each knock seems to "crumble" the idle, did that happen in yours or that's might be my mind playing tricks with me?

Again, thank you all, priceless help! 

[J_Walker]

The cam knocking was fixed on the 05+ bikes, they added this little spring spacer thingy between the right side .. there are 2 spacers and a little spring in-between them.. I guess this keeps the cams from knocking as mine has it, and I wasn't sure why. ^_^

[Kalaazar]

My '92 will make a knocking sound occasionally as well.

Sometimes at idle, it will clunk bad enough that the idle goes WAY down, almost to a full stall.  I will try to get video of it one of these days...

Always wondered if I should be more concerned than I am, but so far so good!  lol

[piresito]

My '92 will make a knocking sound occasionally as well.

Sometimes at idle, it will clunk bad enough that the idle goes WAY down, almost to a full stall.  I will try to get video of it one of these days...

Always wondered if I should be more concerned than I am, but so far so good!  lol

In the worst case scenario, a GS500 engine is not very expensive... lol

I couldn't get a video of mine yet, can't wait to check yours!

[Funderb]

Sometimes at idle, it will clunk bad enough that the idle goes WAY down, almost to a full stall.

That sounds a lot like a backfire. With the stock airbox it sounds like a thunk, with a K&N it sounds like a

"KPAAF"

(Mine does that if you do a certain chain of events, which lead to a no-combustion, then a backfire, a lot like cheat codes on a playstation,
-high revs, coast down, twist throttle, close throttle, open throttle, roll under power at 2krpm, close throttle, POP!)

At idle, the likely culprit is the ignition. Replaces your sparkies and check your coil on the culprit cylinder if this is the case.

to the OP- Your video, if im listening to the right sound, sounds like piston slap or wrist pin knock. That metallic "Tappatappatappa" noise. I couldn't detect any loss or severely lopeyness in the idle.