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A rattle from the engine block...

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by FoxRiderJ, Jul 9, 2011.

  1. First off, got my P's yesterday! Feels good to finally get the yellow monkey off my back.

    Now about a week ago, i started to notice a rattling fromt he engine block; only audible in first and second gear, at high rpm. Not audible in Neutral or stopped dead.

    I got the bike serviced on Thursday from the boys at Close motorcycles, and asked them to look into it. They couldn't figure it out without having to open up the engine, which will cost manual time. But they reckon it shouldn't be an issue.

    What do you guys think? Personally it bothers me that noise wasn't there last week, and i'm tempted to rip apart the covers just to see if there's anything loose or broken. The thing is, especially after the service, she's running better than she's ever ran before.

    The noise sounds like gravel had gotten into the engine block / valves. Imagine a noise of sprinkling gravel on metal. I believe it is a concern for worry despite what the service guys said. She's an Intruder 250 BTW.

    Thoughts?


     
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  2. Sounds like camchain tensioners to me, from the "sprinkling gravel on metal" description.
     
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  3. After a bit more research, it definitely sounds like the tensioner. Anyone here experienced in changing it yourself? Is it a job i can do in my garage?
     
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  4. Depends on how mechanically adept you are. It's not a trivial job.

    There is also the possibility that they advanced the spark a bit, which would explain the better running, but now it can knock or ping or detonate under load. In a mild case, it sounds like autumn leaves rustling in the breeze. In a bad case, it can sound a bit like gravel in the engine. I'm not sure off the top of my head what the easiest way would be to check that idea. In principle, you'd retard the timing a few degrees and go and try it. That might be as simple as slightly moving the crank position sensor, but not all of them are easily moveable.

    I know - What fuel do you run? If it's regular 92, let it get well down and then throw a few litres of 98 in there, and see if that helps. If it makes no difference, it's probably not pinging.
     
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  5. I would like to think I'm reasonably okay, for a garage mechanic anyway, I won't do this alone though, I'll go to the old man's garage where he's got a plethora of tools and and knowledgeable mechanical brain.

    I've been running 95 petrol on her since before the sound starting through, so i don't think it could be pinging? So how do i test the the cam chain? Just mess about with the sensor then test it on a ride?
     
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  6. hmm, got my doubts about the tensioner. Usually when they are noisy the noise is present at idle and goes away at higher rpm.

    Model specific forums may say otherwise.

    What is your bike and how many k's etc? Bikes do change their noise profiles over time, so it may just be fine.
     
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  7. I'm not the best person to give advice on camchain tensioners because I've rarely worked on them and when I have, I've fucked it up. I broke one on a honda 4 many years ago and had it drop the chain while idling at a set of lights. I do agree with ibast - loose camchains tend to make the most racket at low engine speeds and get quieter as the revs build. That isn't something you should take as a reassuring sign - if they're loose then they'll only get worse.

    How would you check it? ... um ... That very much depends on the individual engine, and I'm not familiar with the 250 Intruder at all. I've never ridden one and never touched one. Some engines have little inspection port things where you can get to the valve gear, and you can sometimes get a sense of how tight the camchain is through those. Some types of camchain adjusters can allow you to undo a lock nut and kind of feel what the tension is - others don't work that way. I thought I knew how the one on the honda worked after reading a detailed piece about one on a Suzuki and I broke the fucken thing. There are about 4 or 5 types that are common and a dozen less common ones. Get a workshop manual.

    Anybody here worked on 250 Intruders?
     
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  8. Tricky one. Don't think it's tensioner if it's only at high revs. Don't think it's ignition for the same reason.
    If it's an irregular sound I'm inclined to think it's not a rotating component but that can also be deceptive.
    Is it a high pitched rattle (ie. lighter components) or a deeper rumbly sound? LH (gearshift) side? When it starts does the performance drop a bit?
     
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  9. Check the valve settings. They may need to be adjusted is my guess.
     
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  10. I have to agree with this.
    "Gravel on metal" has got me though - it's exactly what chain slop sounds like.
     
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  11. It's a high pitched rattle, louder on right hand side. It is noticeable at higher revs and not in low, and definitely not there when in Neutral, whether i rev her or not.

    Performance hasn't dropped from what i've seen.
     
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  12. ... damned if I know.

    Sounds like a heat shield on the exhaust or something. Cosmetic cover over engine cover has the glue coming loose... Wire bracket that holds the throttle cable off the exhaust header is loose... I dunno. Header pipe to muffler clamp is loose ...

    It's a b@stard that you can't reproduce the noise in neutral. I mean, that's a valuable clue right there, but it makes finding it just a little bit tricky.

    Does it happen in all gears, or only top gear? Does it happen only at full throttle, or at any throttle? Does it happen at a specific rpm or just anything above a certain rpm? Does it get louder as the revs rise, or does it level off and diminish?

    How old is the bike? (time + km.) How well maintained is it? I mean, do you give it a wash once a week and go over everything you can see and make sure it's tight? If one of te bolts that held on a piece of body work or trim came loose or fell out - how long would it take for you to notice? Did it start making the noise as soon as you got it back from service, or a couple of days later? Have you looked at the airbox and battery cover and all that stuff for something loose? It seems to me that it's related to the work done, and that something has not been put back on right. I'm trying to think what they'd undo and take off. The sidecovers are fitted properly? How does the seat secure to the bike? The rubber top stop hasn't fallen off the centre stand? The drive chain isn't rubbing against the centre stand?

    There are so many silly little things it might be...
     
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  13. Is it dangerous to take the covers off and start her up, rev her in gear to see what the problem may be?

    I might film the whole thing on my camera and upload it here, i don't know if that'll help matters though.

    Thanks for trying to sus it out though, KneeDragon.
     
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  14. Depends on which covers. Don't take off anything that holds the oil in and then start it up, or you'll be cleaning up walls and floors for a month.

    Taking off the sidecovers - just the painted bodywork plastic junk - no, that's fine. I could be wrong, but I have my doubts you'll find it by filming anything. If you can get it to make the noise while the bike is stopped, then you can track it down, but if it only happens when you're moving...
     
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  15. I give her a clean and inspection every Saturday morning, good way for me to sober up from friday night. I haven't had a look at the batter / airbox covers as they're way above where the noise is happening. But i guess its timet o do a process of elimination.

    The noise is audible between 1st - 3rd gear, can't hear it on 4th. Not present at idle but audible once the rpm builds. I'll ride her in to work this morning, it'll give me a good hour to listen to her.

    It would've been so much easier if the noise started after the service had been done, but the reason i took it in the first place was because of this issue, so was happening before i took it in.
     
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  16. Ok. I'm running out of things to suggest.
     
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  17. Can you ride find somewhere quiet and ride it without a helmet?

    I've had noises I would swear were coming from the engine that turned out to be the chain or rear caliper one I took my helmet off.
     
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  18. #18 FoxRiderJ, Jul 17, 2011
    Last edited by a moderator: Jul 13, 2015
    Here's a video of said rattle:

    [media=youtube]LeGJrv9Odcw[/media]

    An update: I've managed to get rid of the 'sprinkling gravel noise', turns out it was my helmet lock rattling against the chrome. (LOL)

    But this is the other noise that concerns me. Sounds like it might be valve related? Any ideas?
     
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  19. Well I'm glad that's all it was!
    And a little embarrassed too...
     
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  20. Tell me about it! Embarrassing indeed.

    Although i notice now there is an odd tick, which definitely sounds more like a traditional cam chain noise. But its very irregular, like two to three ticks every 30 secs or so. I'm unsure if that's worth checking? Supposed to be an auto tensioner in the bike...

    But that rattle persists!
     
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