Tapping/buzzing sound at first start up!

[Big orng]

I bought a used Mx5100 in Nov (128 hrs). Great tractor! We had a cold snap(low 30's) I went to start it after letting the glow plug engage for about a minute I hear a fast tapping sound near the front of the engine. After about 5 minutes it clears up. When it's 50* or warmer you have to have it at higher RPMs to hear it and its duration is shorter. I've changed the oil and added oil treatment, removed the belt from the alternator thinking it might be the alternator but it's still doing it. Someone mentioned a tach drive?? The tach has not been sporadic. But if it is the tach drive is it oiled separately from the motor? If so how do I oil it? It does sound like its near the oil filter. I can almost feel a vibration that matches the sound when I put my hand on it.

Here's a link to YouTube with the sound.
Sorry I'm moving it so much. I'm trying to get different vantage points.
http://youtu.be/lEfjnxNbY68



Thanks for any help !

 

[skyhook]

Didn't listen to the vid, but it could be a lifter or tappet.
They do "tap" a bit when their cold until the oil reaches them.
May just need some adjustment on the tappet. Not sure if their adjustable on yours or not.

 

[m1lkman]

Didn't listen to the vid, but it could be a lifter or tappet.
They do "tap" a bit when their cold until the oil reaches them.
May just need some adjustment on the tappet. Not sure if their adjustable on yours or not.

Im no mechanic but it almost seems belt related...or something attached to the belt like your alternator...Just my 0.02

 

[Cherokee140]

Hard to tell from the video, but sounds like it could be a bearing in your alt, or perhaps a water pump. Take off the belt and give both a spin....see if you hear anything.

 

[Oldtink]

By-pass valve lifting in the oil filter? What weight oil are you running?

 

[rbargeron]

....... I've..removed the belt from the alternator thinking it might be the alternator but it's still doing it. Someone mentioned a tach drive?? The tach has not been sporadic. But if it is the tach drive is it oiled separately from the motor? If so how do I oil it? It does sound like its near the oil filter. I can almost feel a vibration that matches the sound when I put my hand on it...

Great video - it could be a cold-buzzing relief valve but it's a bit loud for that. Still, if you can feel it at the cannister that may be it. A 2ft length of small metal tubing can be used as a one-ear stethoscope - wrap something around the end to protect your ear. Moving it from place to place on a running engine tells a lot.

To check the meter cable you can simply unscrew the collar, pull the cable out and run with it disconnected (oil will not squirt out).

 

[rbargeron]

....... I've..removed the belt from the alternator thinking it might be the alternator but it's still doing it. Someone mentioned a tach drive?? The tach has not been sporadic. But if it is the tach drive is it oiled separately from the motor? If so how do I oil it? It does sound like its near the oil filter. I can almost feel a vibration that matches the sound when I put my hand on it...

Great video - it could be a buzzing relief valve but it's a bit loud for that. Still, if you can feel it at the cannister that may be it. Try a length of small metal tubing as a one-ear stethoscope - wrap something around the top end to protect your ear. Place the other end against the running engine - moving it from place to place will help pinpoint it.

To check the meter cable you can simply unscrew the collar, pull the cable out and run with it disconnected (oil will not squirt out).

 

[Big orng]

Rotella 15w-40. I did notice yesterday when it was warmer out. 60 or so. I started it and it made the sound but only when it was at higher RPM. Sounded normal at around idle and was completely gone in less then 5 min. When I changed the oil I replaced it with the same Kubota oil filter but I'm not sure what weight oil was in it before the change. I wonder it that's what it is? cause it really sounds like its located at the oil filter. I hope its something like that. I guess I'll load it up and take it to town.
Thanks for the information!

 

[Big orng]

Thanks for the advice I'll definitely make the stethoscope. And I'll check the meter cable.

 

[skyhook]

A heavy weight "40" oil in cold temps will take longer to reach the top of your engine,
hence the "tapping", probably not a big deal if thats what it is,
if it runs fine in warm temps, that would be my "guess".
Good luck, let us know what the shop tells you.