Kubota L3710HSTC problem

[Electroman]

Hi everyone!
I am new on this forum, I just bought a 2001 Kubota L3710HSTC tractor with a L682 Loader on it, It have 880Hrs on it and i thinks i have a some problem with it, i'll explain:


First:
When i start the tractor (at -15C), i turn the ignition switch on, the glow plug lite for 4-5sec and after that they turn off, i crank the engine and it take about 10-15sec to start.
when the engine start, there's a lot of black smoke for 2-3sec and after, the engine idle very well and respond to the trottle perfectly.

I think that the glow plug dont have the time to get hot enough in 4-5 sec at that temperature, is there a way to make them lite longer or it is always 4-5 sec??

Second:
The tractor hydraulic and hydrostatic are working good but it is making a strange noise (weird whining or buzzing noise of some kind) coming from somewhere around the hydrostatic unit when i release the clutch (without moving and touching the speed pedal)

The sound is similar to an hydraulic pump running on relief BUT

The hydraulic for the loader work well and have power and speed.
The hydrostatic trans work very well in every range and reverse.
The 3 point work well too at any position and have the power it is supposed to have.
Hydraulic fluid is Full.
The tractor is working well but this noise is loud and anoying.

If any of you have saw something like that before, it would be nice to know what could cause that noise.

 

[Grandad4]

Welcome to TBN. I have an Lxx10 model also, although with a larger engine, but similar to your L3710 in most respects. Just my opinion, but both of your issues sound pretty normal to me. Your tractor does seem to crank a bit longer before starting (10-15 sec), but you are in a much colder climate. If it runs OK otherwise, it can't be in too bad condition. You might try using Power Service diesel fuel conditioner, particularly in cold weather. It prevents gelling of the fuel, controls moisture and seems to make the engine start quicker and run a bit smoother.

As for the "buzzing", you may have some sheet metal vibration that is not related to the hydraulics in any way. My tractor will sometimes buzz like that at certain engine rpm's and it seems to come from under the seat. It has done that since it was new. It's a minor annoyance that I could probably fix but never seem to get around to doing so. As long as your hydraulics and HST are working normally, your tractor may be doing the same thing and it's nothing to worry about.

 

[MapleLeafFarmer]

boujour... -15c is nothing... today -37c here.

for your glow plugs cycle 2 or 3 times before you hit the start.That is glow plugs on, when light goes off turn key off and immediately turn the glow plugs on again until light cycles off. Do this 2 or 3 times depending on outside temp. then tractr fires up after just 2 sec's or so... 15 seconds is to long to crank IMHO.

Forr the noise how long have you let the tractor warm up? I find after letting it warm up for 15 minutes at -15c and most of the noises are gone away. For sure at colder temps the tractors are noiser.

BTW how much snow you guys have? We are bringing a group of Americans to Mt. Valon in a few weeks to take them snowmobiling.

Cheers

 

[john_bud]

I think it's operating normally.

1) in cold temps, cycle the switch several times to activate the glow plugs 2-4 times.
2) The smoke is due to the engine being cold. The fuel is not being completely burned.
3) if you can add a frost plug heater and warm it for a couple hours before starting, it will be "happier"
4) The "buzzing" is the bypass in the HST protecting the filter. I would switch to SUDT fluid or a multi-vis
real synthetic tractor fluid. Amsoil has one that is good, but $$
5) you should use the clutch peddle hook to hold the clutch down and allow the engine to run at 1400-1600 rpm
for 5-10 minutes so it can warm up before moving it.

 

[MHarryE]

Nice weather. We had -27C this morning. My RTV900 took two glow plug cycles to start. When it didn't give a hint of firing after 5 seconds cranking I cycled the glow plugs the second time and it fired right away. I had a L3710 and as I remember it started about how you described until we to our heated garage built so it no longer had any cold starts. Also, Kubota published a chart several years ago showing the advantage of using Super UDT in cold weather. The hydraulic pump has a suction filter and cold oil does not make it through the filter very easily. Super UDT has much improved cold flow characteristics and Kubota says it reduces system noise. I always ran Super UDT in mine even when it was in the heated garage.