Chattering sound when OAT is cold at higher speeds, stops with slower speeds.

[JoBrCo]

Chattering sound when Outside Air Temperature (OAT) is cold at higher speeds, stops with slower speeds.  I'm not sure what it is.  I'm thinking speedo cable, or maybe bearings for the alternator or other bearings (dry).  Of course I'm worried about the failure of whatever it is.

Also I'm getting a knocking sound upon starting, that quits after it catches.  I'm thinking either valves or pistons.  Whatever it is, it's not normal.  It's never done it either before it's 19 year slumber, or when first awakened.  It seems to have gotten worse as I've been riding it.  I've currently been riding in temps as low as 31 F.

FJ Forever! 


TIA


JoBrCo

[FJ1100mjk]

Disconnect speedo cable at wheel, and tie it up so it won't catch on anything. Ride the bike. Confirm or disprove it as a possible source.

[JoBrCo]

Disconnect speedo cable at wheel, and tie it up so it won't catch on anything. Ride the bike. Confirm or disprove it as a possible source.

Good idea on the chattering, I was thinking the same thing, but wanted to seek specific experience before doing so.  If no one has any then I'll definitely try it.  I mean I don't really want to loose the stock speedo, temporarily or permanently, but I've seen that some of you guys have opted for the GPS solution, dealing with dropouts depending upon terrain, which I'll probably do, if push comes to shove. 

THANKS much for your time, it's always appreciated!

And...


Happy Holidays!


FJ Forever!   


JoBrCo

[Burns]

(chatter) does the speedo needle bounce when you're chattering? I agree with the disconnect-to-isolate idea; lube the cable before
              you reconnect.
              Check for loose or broken  fender mounts too.
             
(knock ) Could be one jug is not firing at idle when cold.  Do you have fresh plugs in it?  Could be a bit of crud in an idle circuit, or lots of other things.

[JoBrCo]

(chatter) does the speedo needle bounce when you're chattering? I agree with the disconnect-to-isolate idea; lube the cable before
              you reconnect.
              Check for loose or broken  fender mounts too.
             
(knock ) Could be one jug is not firing at idle when cold.  Do you have fresh plugs in it?  Could be a bit of crud in an idle circuit, or lots of other things.

Actually it bounces sometimes while I can hear no audible chatter, then sometimes it doesn't. I've also heard the chatter without any bouncing.  So, so far I've noticed no correlation, though I wasn't really concerned about it all that much.   My thinking was that all lubes viscosity increases with decreasing temperature, such that when it gets really cold the inner spinning cable is effectively not lubed, in that it temporarily catches then releases, and depending upon my speed the frequency of it catching relatively changes, until of course I get below a certain speed.  The frequency of the chatter does increase with speed.  I think the reason for this is that the inner spinning cable is much like a spring.

Wow with those last words, just now an epiphany, guys... so here's the related question after my reasoning, the inner cable on an 85 FJ has a little washer attached permanently to it so it can only go so far into the outer sheath. Mine is currently at the bottom of the cable, thus creating a spinning motion either tightening or loosening the inner spring, if I spun it 180, placing it at the top of the cable then the spin would do the opposite of what it's doing now, i.e., if it's loosening now it would be tightening after the flip.  Do you catch my drift?  Maybe I should spell it out anyway, as often my omissions create confusion.  If there is a bit of drag due to thick lube, and the direction of spin tends to loosen the coil of the spring, then as it loosened it would effectively expand thus tend to grab on the sheaths inner wall, possibly creating the chatter, if it was tightening the spring, the opposite would be true, the inner spring would effectively contract, thus having more clearance, reducing the possibility of chatter. And finally, the question is, "at which end of the cable is your little permanently attached washer, the top or bottom?"   No I don't expect you to go and check for me, just thinking that some of you may know from past maintenance tasks.  Either way, no worries, as I'll test my hypothesis, the next time I have a little time, by simply flipping the cable over, top to bottom.  Any thoughts on my reasoning?

Also the jug thing sounds reasonable, as she seems to not run on all four reliably at idle, but seems much more smooth at higher RPM's.  I really need to adjust the valves, as I have not, since I awakened her from her slumber, so I'm probably doing more damage to the valves and seats, if she's tight.  I've just been relying on her so much that I don't seem to have the time. I'll have to do the job twice.  Once to measure, and find the required shim values, then after ordering and receiving them, again to replace them and I'm worried about only having one set of new valve cover seals (both the gasket and 8 rubber plugs).  Actually the current set of valve cover gasket/plugs are leaking oil onto the top of the head and burning/smoking.  I want to finish our car, so I can park her and take my time opening the valve cover only once.  I really hate making these kinds of decisions while in a pinch, damned if you do, damned if you don't.   


Again, Happy Holidays!

FJ Forever! 

JoBrCo


     

[FJ_Hooligan]

Cable washer goes at the bottom
Valve cover gasket can be reused many times. Replacement is more a function of age

[JoBrCo]

Cable washer goes at the bottom
Valve cover gasket can be reused many times. Replacement is more a function of age

Thanks for your input, Hooli.  The bottom is where I found the washer, and I usually put things back the way I find them, but you never know, I can make mistakes, obviously.

As far as the gasket goes, You know what they say, while you have a spare the old one will last a lifetime, but as soon as you don't, you'll damage the only one you have.   But yes I was hoping that was the case, that they can be used multiple times, and was actually counting on it.

Meanwhile I found another thread on the forum dealing with speedo cable noise, and cold weather.  So I'm pretty sure that's the issue, without any troubleshooting.  I'm worried about the actual gauge failing as the other thread indicates is probable.  So as soon as I can I plan on pretty much taking everything apart, except the engine, so I can lube anything that requires it.  Also to clean out the cobwebs.

Well Thanks again, as usual I always appreciate it.

Happy Holidays Hooli, and to every one else as well!


FJ Forever!   

JoBrCo