blackninja12
Parking Attendant
Posts: 6
|
posted June 01, 2010 12:28 AM
engine noise
I just got my engine rebuilt (change to another used complete head set excluding cam shafts, cylinder block and pistons after the broken valve incident). Along the way I have changed the timing chain as the old one has going thru about 50K miles.The bike runs great (I has been doing some hard 500 miles) except for some ‘strange sound’ from the engine.
1. When the engine is cold, there is a repeated ‘tack’ sound. The sound maintained even when I hold the clutch all the way in (as some guys would say it came from the clutch housing). The sound much less noticeable and almost disappear after the engine is hot after some riding. All valve clearance has been checked ok.
2. Another thing is when I release the throttle after short rev (in neutral gear), there is a ‘rattling’ sound just before the engine reach the idling rpm again. It does sound like a slack timing chain to me.
Adjusted the timing chain tensioner and crankshaft balancer but there is no difference.
3. All lower engine parts (con rods, bearings, crankshaft) was not replaced when rebuild as the mechanic checked and said there are all still ok.
The mechanic who did the rebuilt insisted that it should be no problem and I can just live with it. Well, I was not so convinced…
Need some advice here on what could possibly be the source? Does anyone else experience the same? How can I get rid of the noise as it is really mind boggling.
  
|
biggmoinc
Zone Head
Posts: 747
|
posted June 01, 2010 04:11 AM
I would've changed all the bearings, unless u take ur motor apart once a year like sum do that is, I would've thought can tensioner, but u said its good n to b honest wit u my 00 12 engine is very noisy, ticks n all, loudest engine I have ever had, it goes away slightly after warming up but it still there, top end sounds like valves n raise n lowers wit rpm's, bottom knocks, lol, I use 15w50 mobile one, I beat on it hard n it holds up so...... imma ride it til it blows
____________
07 ZX14 bmc filter, muzzy m14, 16/44,66",auto shift, 6'3, 204lbs/1.54/3.99/6.03@120/7.8/9.32@147
biggmo@aol.com
|
blackninja12
Parking Attendant
Posts: 6
|
posted June 01, 2010 09:33 AM
Biggmo, are u saying that u probably have the same bearings issue on your engine and u just leave it as it is?
I talked to the mechanic again about the bearings condition and he said it was okay. I think he only did the visual n feel check as he said if there is a loose bearing you can feel a movement when u pull/push the rods..sort of.
Is there other specific ways to check on the bearing condition?
What could go wrong if i just leave it as it is?
Could it be the consequence after I have my piston hammering on the broken valve? (there was a big hole on the piston)
or could the loose bearing is the actual reason I have the piston hammering on the head and valve in the first place?
Sorry if I sound so naive but after spending big bucks on the head n block it seems that I am trying to avoid major repair again...for a time being.
|
Shane661
Needs a life
Posts: 11494
|
posted June 01, 2010 09:35 AM
quote:
Could it be the consequence after I have my piston hammering on the broken valve? (there was a big hole on the piston)
If that took place the bearings needed replaced, imo. You are talking about reducing bearing clearance to ZERO when that happens.
|
biggmoinc
Zone Head
Posts: 747
|
posted June 01, 2010 10:09 AM
 Edited By: biggmoinc on 1 Jun 2010 18:12
no, i'm sayin that since i dont ever go in my motor unless its a clutch issue, if i was to rebuild an engine i would change all bearings, etc, mind as well since its apart, It would be beneficial for u n the long run to change all ur bearings, after the new head n everything it would be insurance n an ease of the mind to swap em out
____________
07 ZX14 bmc filter, muzzy m14, 16/44,66",auto shift, 6'3, 204lbs/1.54/3.99/6.03@120/7.8/9.32@147
biggmo@aol.com
|
biggmoinc
Zone Head
Posts: 747
|
posted June 01, 2010 10:16 AM
put it to u this way, i had blow by around piston rings when i bought the bike n rebuilt the top half n went with a swap in an out 1270 kit, since it came wit pistons n cylinders it was a bolt on replacement, keep in mind the motor had 23k or so miles on it, 1 year later i changed the oil n silver was all in it, come to find out the rod bearings were going, i had to rebuild the entire motor, now i had to pay double for engine removal n replacement when i shouldve done the entire motor from the get go, so what i'm sayin is dont make the mistake i made, it will be cheaper in the end, now i'm upset cause i didnt get a stage 1 head, only smoothed it out, so i'm still not reaping the full benefits of the 1270, oh well, its too late now n i hope i dont have to rebuild ever again, lol,
____________
07 ZX14 bmc filter, muzzy m14, 16/44,66",auto shift, 6'3, 204lbs/1.54/3.99/6.03@120/7.8/9.32@147
biggmo@aol.com
|
blackninja12
Parking Attendant
Posts: 6
|
posted June 01, 2010 04:20 PM
ok, understood biggmo.
Other than bearings would there be other potential causes?.. like piston rings or the pin that connecting the piston to the rod (i am sorry I don't know what is the exact term for that bit)
Normally when we do the bearing replacement, do we only change the one's with problems (on the rod with the damaged piston) or the whole lot?
In my case, do they need to tear apart the whole motor or just the bottom parts and disconnect the timing chain?
Should i just ruled out clutch assembly?
Mine is 02 12 and everything is stock standard.
Thanks again for all the reply
|
biggmoinc
Zone Head
Posts: 747
|
posted June 01, 2010 05:25 PM
Edited By: biggmoinc on 2 Jun 2010 01:27
From my understanding the OEM clutch works fine, a billet clutch basket is a must as well, not dure how strong the 02 basket is , change all the bearings, I did the oil pump, thermostat, plugs, n all bearings, he said it was all good, I said change it neway, why not?
____________
07 ZX14 bmc filter, muzzy m14, 16/44,66",auto shift, 6'3, 204lbs/1.54/3.99/6.03@120/7.8/9.32@147
biggmo@aol.com
|
KZScott
Needs a life
high on speed
Posts: 7235
|
posted June 01, 2010 07:00 PM
show us a pic of the rod bearings that are suspect
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
|
blackninja12
Parking Attendant
Posts: 6
|
posted June 01, 2010 10:43 PM
I can't show the bearing now I am afraid as the bike is still intact. I tried to get opinions by the sounds that i noticed when i rode the bike (like i said above)...before started do anything
|
NINJA12
Needs a job
Posts: 3310
|
posted June 02, 2010 06:45 AM
sounds like piston slap.
It would hurt anything if you let it warm up before you beat on it.
A rod would not stop when warm, it would get worst as the oil thins.
|
dougmeyer
Needs a job
moderated
Posts: 2713
|
posted June 02, 2010 10:15 AM
If it goes away when it's hot, it's likely piston slap. No an issue. You should hear my Z06 when it's cold.
____________
It's not that I think you're dumb, it's just that so much of what you know isn't true....
|
blackninja12
Parking Attendant
Posts: 6
|
posted June 03, 2010 12:54 AM
Ok, I heard about the term 'piston slap' before but really have no idea what it is exactly.
Can someone explain to me what is piston slap?
|
dougmeyer
Needs a job
moderated
Posts: 2713
|
posted June 03, 2010 08:20 AM
When the piston to wall clearance is too loose, the piston rocks and the skirt slaps the cyl wall. It doesn't seem like this should be enough movement to create a noise, but rest assured, it is. As the piston heats up the clearance closes and the noise goes away.
Typically the noise sounds like a muffled metallic hammering which is rpm related up to a point, where it then diminishes. You can really aggravate it if you raise the rpm very slowly and then just let it float with no load at the spot where it seems loudest.
____________
It's not that I think you're dumb, it's just that so much of what you know isn't true....
|
blackninja12
Parking Attendant
Posts: 6
|
posted July 01, 2010 07:31 PM
Thanks guys for all the replies.
I have been checking around for infos in the internets and youtubes on this thing as well. Youtube have a lot of infos and video samples on how it looks or sounds like for all sorts of engine problems.
In my case it could have been any one or combination of the piston slap, rod bearings, and faulty chain tensioner, or clutch/ transmission issues.
Since I tried not to jump into the big job, I got the guy at the garage to open up the clutch and inspect. He checked, take everything off, clean it and put it back on and no change. Then I got him to change the cam chain tensioner as it was not replaced last time. Did that and no change.
Now I am getting him to strip the engine apart and getting it thorough check. He was inclined to suspect on the bad rod bearings though.
Last time I mentioned that there was a ‘tack’ sound when the engine is cold and dissappear as it get hot. After close inspection, actually when it is hot the ‘tack’ sound is gone but the noise is still there. It was less pitchy and the sound was louder on the other side of the engine.
|
|
|
|
|
HOME
NEW TOPIC