3720 (2009) Glow Plug Timing

[9973720wb19]

This is my first tractor and I have a question about the length of time one should pre-heat the glow plug. The manual says 10-15 seconds, however the dashboard readout always shows "Wait" longer than the recomended seconds in the manual. Should I wait until the "Wait" light goes off? I've been just preheating for 10-15 secs. and it starts right up.

Thanks

 

[megotatractor]

I'd say if it starts instantly and runs smoothly with little smoke it's enough time.

 

[beenthere]

I don't think that light will ever go out, as long as you manually hold it on. Don't think in the coldest of temp, I've ever held it on for more than 5-8 seconds. Always starts, and sometimes smokes a bit for short time. That is the 11 yr old Deere 4300 with Yanmar 3cyl. 600 hours

 

[bosshoss]

I don't think your 3720 has glow plugs it is a direct injection engine and has air preheater in the airbox, and that is what you are doing when holding in key running the preheater.
I am not sure of this but I think that is the way it is set up.

 

[soulasphil]

I don't have a 3720 either, but I don't believe there are glowplugs on a turbocharged intercooler diesel. Should start very easily, even in the cold.

 

[Cocre]

My 2006 3320 has no glow plugs, only a manifold heater. Unless they changed something in later years the 3720 won't have them either.

I press the key in and the heater and the dash light turn on. The light stays on until you release the key. 10 seconds is plenty long enough for me.

 

[sunnyside360]

When the temperature is below 35 deg, I hold the key in for about 5 to 8 seconds on my 2007 3720 and it starts immediately. It does not have an engine block/coolant heater.

 

[9973720wb19]

thanks guys. I checked the manual and my 2009 3720 with 60 hours DOES NOT HAVE GLOW PLUS...it says press the key for 10 to 30 secs to activate the intake air heater system. thanks for your help.

 

[Nuru]

When the temperature is below 35 deg, I hold the key in for about 5 to 8 seconds on my 2007 3720 and it starts immediately. It does not have an engine block/coolant heater.

Same here, below 20 deg, starts right up.

 

[KennedyDiesel]

I seldom use my preheat. If it fails to start then I give it a few seconds of heat. It generally pops off cleanly after about 2 cylinders come over center.

 

[Acolar]

I have noticed that on my 3520 when I use the preheat function that the engine starts and runs at an elevated RPM for a pre-determined amount of time. Then it drops back to a normal idle RPM.

I have not experimeneted to see if the outside ambient temp is what determines the elevated RPM or if its the use of the preheat function. I should also measure the time of the elevated RPMs to see if its related to ambient temp (colder it is the longer it runs at evelated rpm)

 

[KennedyDiesel]

The elevated idle is temperature based and not related to preheat function.

 

[ME83]

I have noticed that on my 3520 when I use the preheat function that the engine starts and runs at an elevated RPM for a pre-determined amount of time. Then it drops back to a normal idle RPM.

I have not experimeneted to see if the outside ambient temp is what determines the elevated RPM or if its the use of the preheat function. I should also measure the time of the elevated RPMs to see if its related to ambient temp (colder it is the longer it runs at evelated rpm)

My 110tlb also has an intake heater and does the same thing. It does run at the elevated idle longer when it is colder out, and it is louder when it does too. When the temp is in the single digits it will take about a full minute before the idle drops. When it is in the 30's it lasts for 20-30 seconds. My guess is that it works off of intake air temp/density, and has set times for different temps.

The 110 manual says when it is below a certain temp to hold the key in for 15 seconds and when below another temp to hold it for 30 seconds.

 

[Acolar]

Thanks KD

I was going to place a stop watch in the cab and start collecting times based on outside ambient temps - just for kicks.

 

[KennedyDiesel]

I try to use the fast idle as a measure of when not to move the tractor. I try to wait for it to come down before moving or if I do I take it really easy. The combustion knock/timing rattle can get really nasty if you put it under load while advanced like that.

 

[Acolar]

KD

I agree it sounds nasty during the warmup high idle phase.
I also try and wait for the high idle to come down, although I move it slowly out of the garage to keep the smell and smoke outside the building.