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Discussion Starter · #1 ·
My bike is making an extremely loud knocking noise which I am hoping is the cooling fan.
It kinda sounds like someone banging on a frying pan with a hammer. Just like this: CX YouTube link.



Instead of hijacking the other related thread I just want to know the source of this noise and the cause. Is it the fan itself? Did somebody cock it up when installing?



I would consider the electric fan option but I know I can get an oem fan from my dealer very cheap.
 

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My bike is making an extremely loud knocking noise which I am hoping is the cooling fan.
It kinda sounds like someone banging on a frying pan with a hammer. Just like this: CX YouTube link.



Instead of hijacking the other related thread I just want to know the source of this noise and the cause. Is it the fan itself? Did somebody cock it up when installing?



I would consider the electric fan option but I know I can get an oem fan from my dealer very cheap.


Could well be the fan but if not then Cam-chain renewal time before it eats the engine.



Take fan off,put back together with coolant etc and run for a min or two.If gone you know it's the fan.
 

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Could well be the fan but if not then Cam-chain renewal time before it eats the engine.



Take fan off,put back together with coolant etc and run for a min or two.If gone you know it's the fan.


I have the same noise on my 78 CX 500. The bike has had multiple previous owners, and has about 52,000 miles on it. The noise started last year, and has gotten worse (louder) over time. Last year when it started, I thought my fan might be cracking, so I bought a new one and let myself believe that made a difference, but in retrospect, I don't think it did. A couple of weeks ago it got significantly louder. A week ago my temp gauge stopped working, and I have since ridden it to work (4 miles one way) and back twice. This morning I was checking my valve clearances and noticed a slippery, slimey gray goo on the inside of both the valve covers. There appears to be orange coolant droplets stuck to the inside of the covers as well, which leads me to believe that the goo is a mix of oil and coolant. I looked in the oil fill hole, and from what I could tell, could not see any coolant. I drained the oil (without running the engine to warm it up, as I would usually do before draining the oil), and that looked nice and normal, with no coolant in it.



Any ideas on where/how I am getting coolant under the valve covers? Is that noise the cam chain? Or just cam in general? I always thought it kinda sounded like a bearing going bad. The noise almost seems to come from the middle of the engine - with the ol' screwdriver to the ear and engine trick, the noise seems to be about the same from all sides. Is the noise related to my coolant problem, or just another issue at the same time?



Any help or suggestions are appreciated!
 

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Sounds like you're WAY overdue for major maintenance. If you're using orange coolant, it may be Dex-Cool, which is known to not play nice with seals, like the one at the water pump. I tore down the engine on a parts bike I bought, the thing had Dex-Cool in it. There was milk in the crank, but I chalked it up to the bike sitting under a leak in the guys roof for the winter. What I found was that the mechanical seal at the water pump was leaking a bit (is your weep hole dry...yeah, that's what she said)and the Dex-cool had turned the oil seal behind it to little more than a glob of black goo.



See the other thread on this board about checking the camshaft tensioner with a mirror.



Whatever it is, I would be cautious of continueing to ride it before you get a handle of what's going on.
 

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Discussion Starter · #8 ·
Could well be the fan but if not then Cam-chain renewal time before it eats the engine.



Take fan off,put back together with coolant etc and run for a min or two.If gone you know it's the fan.


Thanks Shep.



I was going to make make my own video until I watched the one above. It's just so identical to mine there was no need. I don't know about you but I've never heard a cam chain like that. It's not a ticking sound it's more like a knock coming from behind the radiator.



I should also say the bike has 26,000 miles and I don't know jack about it's history. I don't know who the previous owner was much less the maintenance history. That's why this project is taking so long. I guess I'm just trying to be thorough.



Mike
 

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Discussion Starter · #11 ·
Rick, I don't know. I've never had the bike hot. I've only ran it a minute or so, ever.








Shep, I've had quite a few bikes and almost all have had cam chains. This CX only has 26k so that shouldn't be a worn out chain. Shouldn't even be a factor in my opinion. If it is that doesn't bode well for the CX. I've got one Honda here now with 51,000 that's had no motor issues or repairs ever. Original clutch, starter, cam chain and tensioner, water pump, never had a seal replaced, etc. The motors never been opened and I think that's pretty normal for Honda really.



Anyway, I'll just go and remove the fan tonight and start it. I'll know in two seconds.
 

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There have been rare cases of the bikes having stretched cam-chains at low mileage.I can only postulate that in these cases the owners,from new,never knew about adjusting the cam-chain and abused the machine/s.
Like my parts bike engine.... 13,000 and the chain was toast. The rest of the engine was very clean though.
 

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Ya. Pressure test your cooling system and start your own thread.
There should not be any coolant in your oil.


yeah, sorry about the hijack. I just got all excited to hear the same noise as I have been hearing. (Though that noise is certainly not one to be excited about!)
 

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Discussion Starter · #15 ·
Okay, I just popped the fan off and started it. It took exactly one second to realize that made absolutely no difference whatsoever. Still bangin' on the bongos like a chimpanzee. Damn!
 

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Okay, I just popped the fan off and started it. It took exactly one second to realize that made absolutely no difference whatsoever. Still bangin' on the bongos like a chimpanzee. Damn!


Engine out job.No biggy with these bikes.Once you've done it once it gets real easy.



I used to use my trolley jack with a 1/4" steel plate welded to the stump but now have a Cycle lift,



http://cgi.ebay.co.uk/1500LB-MOTORB...ACK-LIFT-/380220816243?pt=UK_Motorcycle_Parts



You can use a beer/milk crate as well.
 

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Okay, I just popped the fan off and started it. It took exactly one second to realize that made absolutely no difference whatsoever. Still bangin' on the bongos like a chimpanzee. Damn!
That ain't workin... That's the way you do it
 

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The gray slime you refer to, is a mixture of oil and powdered Aluminum. With too much slop in the can chain, it wears out a piece of the engine casing, ride it no further. If you buy a cam chain "kit" it comes with a new plate and a bolt. It's the bolt the chain is eating into.



This is the plate (with wear mark,).
 

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Huh? For what? Are you being sarcastic?


I was not being sarcastic.It's not as hard as you think and we are here to help.It can be daunting at 1st if you haven't done it.I'm sorry if it seemed sarcastic as it wasn't meant to be.



I and others on this forum and the old one have helped lots of people do these jobs with a very high success rate thus saving money.



This is one of the areas commonly damaged by a stretched cam chain,







Check the oil for copper flecks and also read here,



http://choppercharles.com/cs/forums/145871/ShowPost.aspx
 
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