Possible rod knock - any idea if it's worth fixing.

[jmanz6]

I was riding the last week and thought I heard a slight "thud, thud, thud" sound that was very remeniscent of a rod knock. I was selling the bike, but have recently decided to just keep it and set it up for some touring and now this... I had the top end done last fall due to the PO being a HUGE dumbass but he never got into the bottom end but I don't know what had been done before he got it. The shop I took it to for the top end is out of the question - they treated me like crap so they don't get my business anymore. I don't know if anyone else will be any better but I know I don't want to tackle this myself or it will end up like all the other projects in my garage - half finished and forgotten. So, is it worth getting fixed? How long should it take - most shops will charge a flat shop rate for this work so I am trying to get an idea what I'm looking at. I really like this bike, but my $500 CL bike has become MUCH more than that now and I don't want to put more money into polishing a turd if I don't have to. I ride the crap out of it so it's not like I won't get the use out of it but I'm getting tired of putting money into things. Never know, it may not be as bad as I think, but I'm planning for the worst.

[tkent02]

I was riding the last week and thought I heard a slight "thud, thud, thud" sound that was very remeniscent of a rod knock. I was selling the bike, but have recently decided to just keep it and set it up for some touring and now this... I had the top end done last fall due to the PO being a HUGE dumbass but he never got into the bottom end but I don't know what had been done before he got it. The shop I took it to for the top end is out of the question - they treated me like crap so they don't get my business anymore. I don't know if anyone else will be any better but I know I don't want to tackle this myself or it will end up like all the other projects in my garage - half finished and forgotten. So, is it worth getting fixed? How long should it take - most shops will charge a flat shop rate for this work so I am trying to get an idea what I'm looking at. I really like this bike, but my $500 CL bike has become MUCH more than that now and I don't want to put more money into polishing a turd if I don't have to. I ride the crap out of it so it's not like I won't get the use out of it but I'm getting tired of putting money into things. Never know, it may not be as bad as I think, but I'm planning for the worst.

Pretty sure if ti IS a bad rod, and if you pay some shop to fix it, it will cost a lot more than the bike is worth. You might start looking for a parts bike with a good engine, or someone with an extra engine or at least a bottom end laying around. Probably someone on this GSR has one that's not needed.

[Nessism]

God bless you guys that love old vehicles and dump major dollars into them paying some mechanic to wrench on them for you. That said, this approach to classic vehicle ownership is an express route to the poor house.

My opinion is to wrench yourself, or stick with newer vehicles. Regarding your GS, I’d keep riding it until it’s ready to throw the rod though the cases. At that point you can either replace the entire engine, which isn’t overly difficult, or part the beast out.

[tkent02]

Regarding your GS, I’d keep riding it until it’s ready to throw the rod though the cases.

Good point, it may last years, and it may not even be a rod bearing, could be something else insignificant. GSes are noisy old beasts.

[jmanz6]

Yeah, I'm still not sure it's the rod. I do need to readjust the valves so that may clear it up. That is a winter project so I'm not going to do anything until I at least ge the valves adjusted. BTW, the shop I had do the top end was sooo clueless that when I took the bike back to them because the valve noise seemed excessive, they said that it was supposed to be like that. I later discovered they never released the cam chain tensioner and the chain was whipping around making a terrible sound - I mean really loud. I released the set screw and suddenly my valve/chain noise went away. IDIOTS. I have to do more looking to verify it's a rod. The plan is to ride it until it gets really bad and I hope it's not anytime soon. I do wrench on my other stuff but those are long term projects, I am NOT interested in the bike sitting in pieces for months and months and that is why I would rather have someone else do it. Plus, I am trying to do my part to get the economy moving again...

[doctorgonzo]

Except for an occasional independent old school shop, if the computer can't tell them what's wrong with it, these wrench monkies have no idea how to fix anything. More likely to bugger it up than fix it. I don't even trust local machine shops anymore after an experience with getting a head decked. I send my machine shop work to APE.

[TheCafeKid]

A knocking rod is generally a pretty obvious sound. Does it do it at idle? Increase volume with speed? Does the bike run like crap or seem down on power? In my limited experience, now having repaired/replaced two GS motors with insert bearing failure, if you have any mechanical knowlege at all, you'll know its an insert bearing thats shot. Its gonna sound like a jackhammer soon if it doesnt already, and it wont be long till that cylinder completely destroys itself or the piston therein. Valves will follow if you keep it running long enough, as the piston gets slung up into them. It will be a massive train wreck, and in that light, i wouldnt want to be ON the bike when it happens. Just my .02....

[tkent02]

It will be a massive train wreck, and in that light, i wouldnt want to be ON the bike when it happens. Just my .02....

Where's your sense of adventure?
I have not had this on a bike, but on two different four cylinder car engines the bad rod lasted more than a year, and never failed. One of them, a two liter BMW from the late sixties, when we took it apart it had one of the rod bearings made the old fashioned way, cut by hand from a piece of leather. This car drove a lot of miles this way.

[jmanz6]

I didn't ride it to work today but I will try to get a decent recording of the sound when I get home tonight. To me it seems almost too rythmic for a rod knock but I haven't listened for one in years either. I also am still trying to figure out if it's crank speed based or cam speed based. It's a new sound on this bike so I am still sorting out what it is - plan for the worst, hope for the best.

I was just at the local Suzuki dealer lusting after a '09 V-Strom so maybe I'll just sell this bike for the $500 I bought it for and get a new 'Strom.

[tkent02]

Rod knocks are very rhythmic, constant sound at a constant RPM, and change with RPM, usually louder as the RPM comes up, not always. Might be louder with a closed throttle, might not be. I'm guessing you probably have something upstairs, possibly caused by running with the cam chain loose, possibly valve clearances are still too loose... Could even be the harmless walking cam we hear about sometimes.

[TheCafeKid]

I tend to agree win you Tom. I don't think it's a rod havin never heard it. But a rod knock usually sound most disgusting to the point you know it's bad news. Now I also don't think it's harmless cam walk as the 16v design pretty much prohibits that problem since each cam has four caps instead of two. I would guess on your last valve adjusment you didn't get a tapper adjuster as tight as it probably should have been and it's backed off leaving a valve or valves very lose. I would suggest you look into THAT possibilty rather soon as riding it like that might launch somehing into a very bad place.

[cavehamster]

I didn't ride it to work today but I will try to get a decent recording of the sound when I get home tonight. To me it seems almost too rythmic for a rod knock but I haven't listened for one in years either. I also am still trying to figure out if it's crank speed based or cam speed based. It's a new sound on this bike so I am still sorting out what it is - plan for the worst, hope for the best.

I was just at the local Suzuki dealer lusting after a '09 V-Strom so maybe I'll just sell this bike for the $500 I bought it for and get a new 'Strom.

You can be like me, and have both! The 'Strom is a great machine, 50k miles on mine so far. But the GS is a heck of a lot more fun at the drag strip....

[jmanz6]

I took some quick recordings from the bike after I got to work today. It doesn't seem as noticeable this morning. Now I'm really not sure what it is. Take a listen and let me know what you think. File 01 was taken at about mid cylinder level starting on the left side of the bike going around the front to the right side. The second file was taken at about valve level starting on the right side going around front to the left side.

Engine File 1

Engine File 2

[duaneage]

I think you are worrying about nothing. You're probably hearing the exhaust sound, or maybe the concrete the bike is parked on is making noise.

[blowerbike]

cover the opening in the exhaust fully with an old towel or what ever.
at this point you should only have internal engine sounds...nothing else.
listen closely and then start rolling the throttle open a little at a time..listen.
blip the throttle a couple times...listen.
by now the old towel should be smoking...
shut off the bike.
what did you hear????