What's this engine noise? (example video)

[dmartins]

Hi everyone,

My 2007 GS has some engine noise that has me a little concerned. It sounds to me like it's coming from the top-end and it varies directly with engine speed. Maybe it's normal for this engine but I'm not sure!

I searched youtube for videos of the GS and came up with the (excellent) review done by mister. His bike has the same sound! I think it is most noticeable and isolated in the section near the start where he rides up from in the distance.

My best description of the sound is that it's a very quick sh-sh-sh-sh-sh-sh-sh-sh. Please have a listen to the first 30 seconds or so and let me know what you think!
http://youtu.be/AzTpSMWFhbY

I have put about 4000km on the bike since buying it at the end of April but I didn't notice the noise at first. That's not to say it wasn't there. Maybe I was just more concerned with learning to ride and not really paying attention to the sound of the bike  

Two changes I can think of:
I ran the oil down to the low mark after a long weekend trip from Ontario down to Pennsylvania. I have since topped it up and the noise remains.
I switched from premium (91 octane) to regular (87 octane) after reading that Suzuki recommends regular for this engine.

Thanks,

Dan

[Twisted]

This is the normal GS sewing machine sound that it produces with the stock exhaust.

[ben2go]

If your valves are adjusted correctly,then it is probably cam walk,which is normal on a GS.Our bikes have nothing to hold them in place except the timing chain gears,so they move just enough to cause a little noise.No engine has had a failure because of it.At least none have been reported.

[Twisted]

If your valves are adjusted correctly,then it is probably cam walk,which is normal on a GS.Our bikes have nothing to hold them in place except the timing chain gears,so they move just enough to cause a little noise.No engine has had a failure because of it.At least none have been reported.

Cam end float noise is a pretty distinctive knocking noise. When it happens it sounds like you have run your engine low on oil. When it first happened to mine I thought I had done this.

[dmartins]

Thanks for the replies.

From what I've read and videos I've watched, cam end float is usually a periodic "tap-tap-tap" sound. My bike doesn't have that. It's just a constant sound that varies with engine speed. I was wondering if it indicated something was out of adjustment or needed replaced. Cam chain, valve adjustment, etc..

I guess a sewing machine noise is a good way to describe it 

[Twisted]

It is a completely normal GS noise. 

[dmartins]

Thanks Twisted! I will quit worrying about it and just go ride!

[sledge]

Cam float? on an `07?........very unlikely, the shafts were modified from `05 on to eliminate the problem.

[Twism86]

Im glad to know that strange knocking/ taping is normal

[ben2go]

Cam float? on an `07?........very unlikely, the shafts were modified from `05 on to eliminate the problem.

Do you know if there are and other differences?Will they work in older heads?

[Twisted]

Cam float? on an `07?........very unlikely, the shafts were modified from `05 on to eliminate the problem.

Think you miss read the thread. The OP's bike does not have cam end float noise. Ben mentioned it could be, I explained that it was a totally different noise than the one the OP was questioning. Mine is an 04 that gets it occasionally.

Do you know if there are and other differences?Will they work in older heads?

I think they fixed the problem with shims Ben from 05 onwards

[ben2go]

Cam float? on an `07?........very unlikely, the shafts were modified from `05 on to eliminate the problem.

Think you miss read the thread. The OP's bike does not have cam end float noise. Ben mentioned it could be, I explained that it was a totally different noise than the one the OP was questioning. Mine is an 04 that gets it occasionally.

Do you know if there are and other differences?Will they work in older heads?

I think they fixed the problem with shims Ben from 05 onwards

Ahh yes,thrust shims.I could do that.

[gsJack]

Cam float? on an `07?........very unlikely, the shafts were modified from `05 on to eliminate the problem.

Think you miss read the thread. The OP's bike does not have cam end float noise. Ben mentioned it could be, I explained that it was a totally different noise than the one the OP was questioning. Mine is an 04 that gets it occasionally.

Do you know if there are and other differences?Will they work in older heads?

I think they fixed the problem with shims Ben from 05 onwards

Ahh yes,thrust shims.I could do that.

My 97 GS bought new had a knocking camshaft that went away and so did my 02 GS.  I checked the 97 and one camshaft had more sideplay than the other.  I broke the 97 in on 10W-40 oil and ran 15W-50 synthetic for 50k miles and then went to the 15W-40 heavy duty oils.

My 02 GS had the knock occasionally when I first got it used with 4k miles on it and after I changed the oil to the 15W-40 heavy duty (Delvac 1300 or Rotella) it hasn't knocked in the over 80k miles since. 

I wouldn't worry about it in any event since it's harmless.  Only knocks when engine is hot and at idle and goes away as you pick up the revs to a fast idle or faster.  Obviously the centrifugal force of the running camchain tightens it up as speed picks up and the camshaft can't wonder back and forth any longer.  All very harmless but an oil change might fix it.  Neither of my well used and well worn GS engines knocked again after I went to the Heavy Duty (truck/diesel) oils  I never worried about the noise once I determined what it was.

[gsJack]

ben2go, the factory fix for new F bikes fixed on warranty was covered by this service bulletin:

http://www.sportbikes.net/forums/attachments/suzuki-line/107537d1166036602-gs-gsx-gsx-r-139-revised-gs500fk4-k5-engine-knock-idle-asmc_004983.pdf

I think you can find some different size shims on the parts fiches for older bikes if you want to try to fix it but an oil change would be simplier if it works for you too.

[sledge]

Cam float? on an `07?........very unlikely, the shafts were modified from `05 on to eliminate the problem.

Do you know if there are and other differences?Will they work in older heads?

The mod/kit doesnt remove the float, it serves to preload the shafts in one direction and provide some resistance against movement. There must be some float there to allow for thermal growth in the shafts. The spacers and wave washers are not interchangeable with the older type shafts owing to the lack of a shoulder on the shafts for them to act against.

[ben2go]

ben2go, the factory fix for new F bikes fixed on warranty was covered by this service bulletin:

http://www.sportbikes.net/forums/attachments/suzuki-line/107537d1166036602-gs-gsx-gsx-r-139-revised-gs500fk4-k5-engine-knock-idle-asmc_004983.pdf

I think you can find some different size shims on the parts fiches for older bikes if you want to try to fix it but an oil change would be simplier if it works for you too.

Thanks.

Cam float? on an `07?........very unlikely, the shafts were modified from `05 on to eliminate the problem.

Do you know if there are and other differences?Will they work in older heads?

The mod/kit doesnt remove the float, it serves to preload the shafts in one direction and provide some resistance against movement. There must be some float there to allow for thermal growth in the shafts. The spacers and wave washers are not interchangeable with the older type shafts owing to the lack of a shoulder on the shafts for them to act against.

Thanks.




Correcting it is not really a concern.I just thought I would do it next time I have my engine apart.I have one engine that I am going to do a top end on next year,so why not.If the cams are out of spec,I will get the parts.I may tear that engine down and do a complete balance and blue print.Gotta wait and see where my GS trike project is at.