engine clicking noise

[spoon_911]

I've got a 2010 nytro mtx with a clicking type of noise in the engine. I've tried a permatex gel locktight on the crank splines/didn't make a difference, also makes the noise with the primary clutch removed. I have taken the engine almost completely apart except pulling pistons out and head off block. bearings and everything else looks to be ok. Replaced oil pump chain, timing chain and tentioner, also only has 800kms on it. Any ideas would help me out alot, Thanks!

 

[spoon_911]

 

[nate007]

Says the video is no longer available, did you figure the issue out?

Sent from my SM-N910R4 using Tapatalk

 

[spoon_911]

https://youtu.be/66bwdtuLUck

No haven't figured it out yet

 

[Off Trail Mike]

Spoon
If the clicking is only at low rev's it's probably the crank spline and there's basically nothing that can be put in the spline to stop it permanently. Good news is it doesn't cause any damage either. Removing the clutch will only make it worse as the crank oscillations are even more free to do their thing. With the belt engaged, it acts like a damper for the spline and it should go away as revs increase. I have it bad on my 11 MTX and didn't have it at all on my 10 XTX...

If you have the "clicking" all the time, it's something else.

And that's about the limit of my knowledge lol....

Good Luck
OTM

 

[spoon_911]

Spoon
If the clicking is only at low rev's it's probably the crank spline and there's basically nothing that can be put in the spline to stop it permanently. Good news is it doesn't cause any damage either. Removing the clutch will only make it worse as the crank oscillations are even more free to do their thing. With the belt engaged, it acts like a damper for the spline and it should go away as revs increase. I have it bad on my 11 MTX and didn't have it at all on my 10 XTX...

If you have the "clicking" all the time, it's something else.

And that's about the limit of my knowledge lol....

Good Luck
OTM

I just ran it again tonight and noticed that it seemed to get quieter once it got to operating temp. Also noticed that noise was there at 1500 rpm and 100% gone at 3100 + rpms, still debating whether to strip it down again too look for something or if this is normal.

 

[Mtnviper]

That sounds like it could be a valve tick. You might try using a mechanics stethoscope and touching it to different parts of the engine to see where can be heard the loudest.
Was there any prior engine work done to it before it started making the noise?

 

[spoon_911]

That sounds like it could be a valve tick. You might try using a mechanics stethoscope and touching it to different parts of the engine to see where can be heard the loudest.
Was there any prior engine work done to it before it started making the noise?

I tried with a stethoscope but its hard to tell if its upper or lower, To my knowledge there hasn't been any prior engine work. Only has 800kms considering I've heard these were very strong engines. What would cause a valve tick?

 

[bholmlate]

That is a distinct tick i was thinking the same thing as MTNViper see if you can pin point where it is internally by listening with a stethoscope. maybe a broken spring in the valve train things expand when things get up to running temp so tolerances get tighter in certain part of the motor. I would start in the valve train though if you have not already gone through to make sure the valve are all adjusted and are at spec.

 

[spoon_911]

That is a distinct tick i was thinking the same thing as MTNViper see if you can pin point where it is internally by listening with a stethoscope. maybe a broken spring in the valve train things expand when things get up to running temp so tolerances get tighter in certain part of the motor. I would start in the valve train though if you have not already gone through to make sure the valve are all adjusted and are at spec.

I have had the cams out when I did the timing chain and buckets off the valves, the valve lash was in spec, unless I should tighten it up some?? Can the cams be removed without removing the tentioner?

 

[Mtnviper]

If they are with in spec, I would not tighten them up as this could cause piston to valve clearance and valve sealing issues. I have heard a bent valve cause a tick very similar to this before. The valve stems are very small in diameter. If there was prior engine damage or engine work done before you got the sled, a valve stem could have been easily tweaked in the process causing it to hang in the guide and tick.
The noise is not normal and my next step would be to pull the head and valves to check them for straightness. If it does have a bent valve and the engine is ran at higher rpm, the bent valve can hang up in the guide allowing the piston to contact the valve head. When this happens the head of the valve can break off and severely damage the engine.


Edited: for updated info from your previous post

 

[spoon_911]

If they are with in spec, I would not tighten them up as this could cause piston to valve clearance and valve sealing issues. I have heard a bent valve cause a tick very similar to this before. The valve stems are very small in diameter. If there was prior engine damage or engine work done before you got the sled, a valve stem could have been easily tweaked in the process causing it to hang in the guide and tick.
The noise is not normal and my next step would be to pull the head and valves to check them for straightness. If it does have a bent valve and the engine is ran at higher rpm, the bent valve can hang up in the guide allowing the piston to contact the valve head. When this happens the head of the valve can break off and severely damage the engine.


Edited: for updated info from your previous post

Just a quick question before pulling the head off. Would it be possible to do a compression test to pin point what valve/cylinder is most likely the problem? If it is bent a little shouldn't it have lower compression?

 

[Mtnviper]

You may be able to detect it with compression test if it's leaking bad enough. A more accurate way to check it would be to do a cylinder leak down test and listen for air leaking past the valves through the throttle bodies and exhaust system. Here is some info on how to perform a leak down test http://www.hotrod.com/how-to/engine/116-0406-cylinder-leakdown-tester/ the article is for automotive use, however the principles are the same for sleds and bikes also.

 

[spoon_911]

You may be able to detect it with compression test if it's leaking bad enough. A more accurate way to check it would be to do a cylinder leak down test and listen for air leaking past the valves through the throttle bodies and exhaust system. Here is some info on how to perform a leak down test http://www.hotrod.com/how-to/engine/116-0406-cylinder-leakdown-tester/ the article is for automotive use, however the principles are the same for sleds and bikes also.

Thanks! Very good link, I think I'll try a leak down first, I'd really hate to tear it down again and find nothing.

 

[spoon_911]

Do I need the M10 long reach or standard compression adapter?