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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> clacking engine noise /cgi-bin/YaBB.pl?num=1346205793 Message started by MeLikeBike on 08/28/12 at 19:03:13 |
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Title: clacking engine noise Post by MeLikeBike on 08/28/12 at 19:03:13 I've posted before, but since I just took a video I've decked to make a new thread. Loud clacking coming from left side of engine, upon closer listening, the most offending/alarming part is a jackhammer-like sound about halfway down. It's very clear with mechanics stethoscope. Somewhere between a "ting" and a "tang". https://www.youtube.com/watch?v=fvSnOMXklt0 sound clearest at 0:19. It's an 2003 with now 5500mi bought last Aug at around 4400 off craigslist for 1700. My uncle thought maybe it was run without oil due to the bluing on the exhaust. But I've changed the oil twice since I got it. I checked the oil for flakes and there is a little that I can get with a magnet, and I can see some on the filter. But I don't know if its excessive or just normal wear. Its my first bike so I can't comment on any low or loss of power...its still a blast. Its just loud and I'm concerned with destroying it and/or me. Exhaust pipe seems fine, and i put on a new gasket. I checked the cam tensioner, and it's fine. I had the valves checked and set to spec last winter at Benteleys in Murrysville PA. The guy at the repair shop/dealer said it sounded loud enough for him to call Suzuki and ask, and Suzuki said "they're just loud". But in he end the repair guy didn't say anything needed fixing. Thoughts? I'm reluctant to tear down the engIne due to lacks of clean workspace, patience, time, and desire to spend lots on parts. But maybe that's what I gots to do? |
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Title: Re: clacking engine noise Post by Paraquat on 08/28/12 at 19:49:48 https://www.youtube.com/watch?v=ZSKo7qQH3hE Sound like that? Edit: Nevermind. You just said you checked the tensioner. --Steve |
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Title: Re: clacking engine noise Post by verslagen1 on 08/28/12 at 20:07:29 you need a mechanic stethoscope got to hunt down the clacking top end will mean worn cam journals bottom end probably burnt piston by the oil filter is the cam chain. |
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Title: Re: clacking engine noise Post by Dave on 08/29/12 at 04:52:24 My engine had a horrible clack....and I found that my left crank bearing was a bit loose, and the worst part was that the flywheel nut on the left side of th engine was only finger tight and should have been torqued to 100 foot pounds. My suggestion is to check the flywheel nut - only downside is that you are going to need a puller for the alternator rotor, a holder for the flywheel, and a 46 mm deep socket. It will probably take an hour or so to try this out and see if that is the problem. I have the tools and would be willing to rent them out for a depost and $ 10 rental fee, and you pay shipping cost both ways. |
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Title: Re: clacking engine noise Post by MeLikeBike on 08/30/12 at 18:42:18 I did get a stethoscope, just to maybe help track this down, and I pulled the tubes off the earpieces and held it near my phone's mic. This video is a reasonable (for a phone) demo of what you hear in the earpieces. http://youtu.be/5PVlrFHEmDA The sound is definitely near the top. Not sure I trust the loudness of the engine cover (since it's like a big bell), but the hammer on metal sound is definitely ringing in there. No comparable sound from the exhaust or frame (or crankcase) |
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Title: Re: clacking engine noise Post by justin_o_guy2 on 08/30/12 at 18:53:03 I think it sounds okay, but, Im not there to be sure. If youre really concerned, go in & check the valves. If theyre loose, adjust them, if theyre inside the specs then set the valves a coupla thousandths tighter than minimum spec & fire it up. If the noise is much diminished, you found it, its just that noisy valve train. Then set them back to spec, on the tite side. |
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Title: Re: clacking engine noise Post by verslagen1 on 08/30/12 at 18:53:16 didn't hear anything really out of the ordinary. definitely higher than lower though. also the sounds are different with the rod vertical than horizontal how about giving us a pic how you did that? might be good for everyone to do the same so they have reference to how it should sound. |
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Title: Re: clacking engine noise Post by MeLikeBike on 09/03/12 at 17:48:17 Well, I dived in and checke the valve clearances. The intake ones were to spec, and so I assume the exhaust ones were as well (but I ended up resetting them, because I loosened everything up to figure out where I needed to slip in the feeler gauges. It wasn't obvious, and it was really hard to do with the motor still on the frame.) So I'm back to spec, and no difference really. I threw in some Rotella T (I read the Great Oil Debate a few nights ago), so at least I'm not doing any more damage. As for how I took the audio, I'd take a picture, but I doubt you could consider it repeatable, since every phone is going to be different, and I don't know how much the tube from the steth was moving around relative to the mic hole. Probably about half a centimeter. So now my question is, if the sound is "loose valves", does that mean it's that few thousandths of play at TDC just rattling somethin' serious? What the the purpose of that clearance? If there's that much banging, then how dangerous is it to shrink it back to, say, .0025"? Could it be that the "spec" is just not ideal for whatever tolerance stackup my bike would be suffering from? |
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Title: Re: clacking engine noise Post by justin_o_guy2 on 09/03/12 at 23:27:08 The reason there is slack in the valves when its cold is, the valve stems get longer when they get hot. That closes the gap up some,.The tighter ya set the valves, within spec, the quieter it is. |
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Title: Re: clacking engine noise Post by cafecarl on 09/04/12 at 07:11:21 213E383F22251424142C3E32794B0 wrote:
+1. But be careful, you also need to keep in mind that if you over- tighten, the valves will hang slightly open and cause compression and combustion problems. I'd stay off the margins. |
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Title: Re: clacking engine noise Post by LouSiana on 09/04/12 at 14:19:28 716E686F72754474447C6E62291B0 wrote:
not quite right, Sir! Since valves and rockers always have to have some clearance, just to assure the valve springs can close the valves everytime they have to. In fact the construction in the S40/Savage is that way, that valve clearance increases with increasing temperature of the enginge parts. Not alone the valve stems get elonged on higher temperatures, the head material (aluminium) does, too! And the thermal expansion coefficient of aluminium is more than twice than steel. Thsi should make clear facts, that "Elsie" usually has the valve ticking sound louder when she is hot. The head is made of cast aluminium and therefore it lifts up the camshaft more than the valve stems can elongate. ;) Back to S40: The specs say a clearance ,08 mm to ,13 mm. ,10 mm is a good middle course. It should be more of concern that both valves are at very same clearance than exactly ,10mm. Intake may be adjusted with lower clearance since they do have lesser temperature stress. There may be different construction features in other engines, where valve clearance decreases with rising themperature. Then they mostly are designed to have adjusted valve clearance at operating temperature or, assuming the difference to room temperature is well known, the valve clearance can also be adjusted to a greater gap when "cold". We had some odd apperances and experiences with that theme on different engine types when I was in apprenticeship on Volkswagen, Audi and Porsche back around 1980 |
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Title: Re: clacking engine noise Post by LouSiana on 09/04/12 at 14:28:21 4F2B646961606B050 wrote:
Not only that. You then would risc a break away of the valve disc. The valve disc uses a good amount of heat dissipation on the valve seats! If it can't do so, the lower part of the valve stem gets overheated, looses rigidity and breaks off. |
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Title: Re: clacking engine noise Post by justin_o_guy2 on 09/04/12 at 16:24:27 The head is made of cast aluminium and therefore it lifts up the camshaft more than the valve stems can elongate. Wink Thats interesting. & the intake is sucking cool air past it, so its cooler than the head, while the exhaust is having hot air blown past it, so its hotter than the head. Its gonna take a while for me to digest that, but not near as long as it takes for a piston to digest a valve head. I hope others chime in here, |
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Title: Re: clacking engine noise Post by MeLikeBike on 09/05/12 at 19:21:19 Great discussion..I love this board. Now...now that I've adjusted myself ( ;) ), I noticed when riding tonight that it's taking a little longer for the engine to slow down after I let go of the throttle in neutral (or with the clutch in). Maybe 2 sec instead of 1 sec (that's a really rough estimate from memory). It changed enough for me to notice. Is that an issue? In general, the bike definitely seems to sound different...a little throatier. Still the tick-tacking, but I think i'm gonna embrace the sound as a high-pitch overtone to my revving exhaust note. |
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Title: Re: clacking engine noise Post by justin_o_guy2 on 09/05/12 at 20:47:52 Engine off, twist the gas, let go, watch the throttle plate on th carb.. it otta Slap shut., If its actin right & the return to idle feels slow enough to feel wrong, then it sounds like a sticky slide. |
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Title: Re: clacking engine noise Post by MeLikeBike on 09/17/12 at 05:22:24 Hmmm...now that i've been riding it a bit, the slow-rundown seems to have resolved itself. However, sewing machine-like valve noise is same as ever (interesting how variable it is, only partially related to temperaturs). Anyway, I've noticed a bit more backfiring. Not sure if it's because I'm being a bit less cautious in shifting (because I'm getting more comfortable riding), or if it's my new and maybe-improved(??) valve clearances. Should I jump into tuning the carb? It looks like the previous owner may have already taken out the brass plug for me. Can the adjusted valve clearances affect the backfiring amount? (It seems that it would, but I'm a software guy, not a hardware guy ) |
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Title: Re: clacking engine noise Post by ToesNose on 09/17/12 at 06:23:54 The more frequent back firing might just be because the temps in your area have dropped, mine has been more this past week or so with the drastic drop in temps. |
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Title: Re: clacking engine noise Post by justin_o_guy2 on 09/17/12 at 08:38:31 Have ya tried shifting w/o the clutch yet? |
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Title: Re: clacking engine noise Post by LouSiana on 09/17/12 at 14:54:48 495650574A4D7C4C7C44565A11230 wrote:
in cases of backfiring that would help like driving with fingers stuck in his ears. ;) Remove the cause, not the symptom! |
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Title: Re: clacking engine noise Post by ralfyguy on 09/17/12 at 15:21:47 Mine backfires/afterfires only when closing the throttle and coasting and the engine rpm's drops down to about a little over 3,000. Not above and not below that. |
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Title: Re: clacking engine noise Post by justin_o_guy2 on 09/18/12 at 05:03:35 183B21073D353A35540 wrote:
in cases of backfiring that would help like driving with fingers stuck in his ears. ;) Remove the cause, not the symptom![/quote] Thanks, but I actually have a clue, & was in search of another, |
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Title: Re: clacking engine noise Post by MeLikeBike on 12/05/12 at 18:37:31 An update... Inspired by Chris Roth's post on a similar issue, I decided to check *my* decompression shaft. So I figured I'd give it a shot. Since the manual says that it might be possible to remove the cylinder head cover without unmounting the engine, I thought I'd try. I succeeded! It was not easy, but only 10minutes of gymnastics got it off. Upon initial inspection I didn't see anything obvious, but then looking on the bottom of the rocker arm, where it rides on the camshaft, I noticed that it was CONCAVE rather than convex, like the intake valve. And there was a thin, sharp sliver on the edge of this, which likely (to my software engineer eyes) means that the camshaft was grinding that sucker down while the previous owner was running without oil. And that the new free space give the rocker arm a lot of room to buck about in a way that was not intended. (When I bought the bike, my uncle took one look at the bluing on the pipe and said "I think that bike's been run without oil.") So I've ordered a new rocker arm (and some red Permatex). The camshaft doesn't seem to be obviously bad (It's still in the engine with the chain on it, so it's just been visual/feel to evaluate it). The rocker arm pad is ground down about .75mm. So I'm hoping for some advice....Can I get away with just replacing the arm (and checking the other stuff in the head cover), or should I really look for more trouble by taking off the engine? Taking the head cover off wasn't so bad, but I wonder how easy it will be to get the cover back on without botching the sealant. I know to the veterans around here, it's a no brainer, because they probably have engines sitting on their coffee tables ;) But I don't want to get overrun with parts everywhere in my garage, and I don't want to get in over my head. Thanks for your support! |
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Title: Re: clacking engine noise Post by MeLikeBike on 01/09/13 at 19:56:29 UPDATE: Put it all back together. Sounds F#$*in' AWESOME!!!! I'm so psyched for the upcoming warm weekend (relatively) in the Burgh to take her out. It was the rocker arms (see my post "Rocker Arm design change" for details). Now I have to just remember how all the wires were strung (please see my latest post to help me out :) ) |
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Title: Re: clacking engine noise Post by MeLikeBike on 01/12/13 at 13:48:38 Took the bike out now that it's back in action, and it runs great. Sounds great (if you like quiet...maybe I'll look into the dyno ;) ) Seems to have a shade more power as well. Thanks to this forum, I fixed the dang thing. I'd never have had the confidence or the knowhow to work on this bike if it weren't for suzukisavage.com, for sure. |
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