JD4100 Glow Plugs?

   / JD4100 Glow Plugs? #1  

GaryM

Veteran Member
Joined
May 7, 2002
Messages
1,327
Location
Warrenton MO
Tractor
JD4100 Hydro
I have a 4100 and am wondering why it does not need/have glow plugs. Last fall before I bought the JD I borrowed a NH of similar size and it did have glow plugs.

Just wondering why the difference. The folks I know with diesel trucks all have glow plugs.

No complaints, just looking for an explaination.

Thanks
 
   / JD4100 Glow Plugs? #2  
Gary - Generally, diesel engines come in two groups, based on the type of fuel system / combustion that they have:

1. Direct Injection (DI): High pressure fuel is directly injected into the combustion chamber. No glow plugs are required. This is the most efficient method, and the most common on today's larger (50hp & up) engines. It does require a more expensive injection pump to develop the pressure & accurately deliver the fuel. It also requires good quality & clean fuel (easy in NA, but not worldwide). Due to speed of injection & the lack of glow plugs, these types of engines will often produce white smoke (unburned fuel) during a cold startup.

2. Precombustion (PC): Medium pressure fuel is injected into a precombustion chamber, where the heat is initially generated, then the fire, fuel & expanding gasses travel out to the main combustion chamber (where they complete their burn as they mix with additional fresh air). This combustion type generally requires glow plugs. It is also slightly less efficient, but can burn any fuel you can get your hands on.

The above two types are general rules, and there are many examples around the world where many manufacturers have tried variations of the above two groups. Interestingly, in an effort to improve the efficiency of gasoline-powered engines, several manufacturers are testing DI-type systems (today's fuel injected gas engines are very similar in concept to the PC system, other than that the fire is not started until the spark is generated).
 
   / JD4100 Glow Plugs?
  • Thread Starter
#3  
I remember reading in the brochure for the 4000 series that they mentioned Direct Injection, except for the 4100! Based on that I'd guess that the 4100 used the Precombustion system that you explained.

The NH that I borrowed is similar in size to the JD4100 and it had glow plugs.

Are JD4100s hard to start in cold weather because they don't have glow plugs? Is there a block heater in my future?

I'm in Eastern MO and the tractor will be indoors during the winter. but not heated. I have seen temps of 20 in my garage.
 
   / JD4100 Glow Plugs? #4  
The 4100 is built entirely by Yanmar and the remainder of the 4000 series having just the engine built by Yanmar. The majority of Yanmar tractors do not have glow plugs. Some have a cold starting aid called "Thermostart". I have never had any problems starting the engines without glow plugs. Of course I live in north Alabama and it does not get as cold here as it does for some of you up north. I have started these engines with the temps in the teens, but those temps don't stay around long here.
 
   / JD4100 Glow Plugs? #5  
The 4100 does have glow plugs. They are activated by turning the key, typically time-out in a few seconds (you can hear the click), then you turn the key to crank the starter. I read this in the owners manual. Did you think the glow plugs were not used because there is no seperate switch for them , and the blue tractor has a seperate switch? I do not know if the automatic operation can adjust for the temperature if you are operating in very cold temps. I cant remember if the manual addressed this.
 
   / JD4100 Glow Plugs?
  • Thread Starter
#6  
Tonight after work I'll turn on the switch and listen for a click after a few seconds.

On the NH I borrowed I was told to turn the key CCW and wait for the light to go out, then turn the key CW to crank and start.

Thanks for the additional information
 
   / JD4100 Glow Plugs? #7  
"The 4100 does have glow plugs. They are activated by turning the key, typically time-out in a few seconds (you can hear the click), then you turn the key to crank the starter. I read this in the owners manual. "

When I first read the original post on this thread, I went to JD's online manuals. They don't have one for the 4100 but they do for the 4100N (Narrow), which is the same machine.
I looked specifically for glow plug info. I couldn't find it...cold weather starting didn't address glow plugs at all.
Really surprised me!

The "click" mentioned in an earlier post may be explained by this quote from the 4100N Manual:

<font color=red>""ON" Position - Move key from "OFF" to this position and the Engine Oil Pressure Light and Battery Charging Light will turn on. You will also hear the engine fuel shut-off solenoid engage with a CLICK. "</font color=red>

The only mention of cold starting aids is:

<font color=blue>"Cold Weather Starting Aids
RECOMMENDATIONS:

· Install optional engine block heater if you operate tractor in temperatures below -18° C (0° F).

· Install optional hydraulic oil heater if you operate tractor in temperatures below -18° C (0° F). "</font color=blue>

So, per the manual, the 4100 does not have glow plugs.

The 670 model tractor I own uses glow plugs (called the Thermo-Start System). One turns the key counter-clockwise (and holds in that position) for up to 20 seconds, then turns the key clockwise to START.

I use it when the temperature gets below 35° or so. However, I don't really think I'd have to...engine starts that easily. I believe the 670 and 4100 engines are very similar, if not identical.

I suppose Deere figures these engines start easy enough to not require glow plugs.
 
   / JD4100 Glow Plugs? #8  
I don't know about the JD670 but on the JD855 I had with a Yanmar diesel, it had thermostart, but it was not glow plugs. It was a small heating element at the mouth of the intake manifold. Instead of heating glowplugs in the combustion chamber, it heated up the air in the intake to help it start.
 
   / JD4100 Glow Plugs? #9  
"I don't know about the JD670 but on the JD855 I had with a Yanmar diesel, it had thermostart, but it was not glow plugs."

Yep, you're right. I've the same thing.I misread the manual.
 
   / JD4100 Glow Plugs? #10  
My partsbook shows three (3) glow plugs per engine on the 4100 CUT
 
 
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