Operating temperature for New Holland TN 70

[RW444]

Replacing temperature sensor for the fourth time. This time going with mechanical gauge.

Anyone know what normal operating temp. is for this tractor?

Thanks

 

[RjCorazza]

I have no information specific to your machine, but you can start with finding the thermostat opening settings and go from there.
For example, my tractor thermostat starts opening at 180f and is fully open at 203f. The manual declares the engine as overheating at 214f.
There also may be specs about the coolant sensor for your machine that may help. I've never looked into the sensors though.

 

[Jerry/MT]

Replacing temperature sensor for the fourth time. This time going with mechanical gauge.

Anyone know what normal operating temp. is for this tractor?

Thanks

The sensor is merely a temperature sensitive resistor that controls the current through the gauge. Generally, they either work or they don't, Why do you think the sensor is bad? What are the symptoms?

 

[Roadworthy]

Operating temperature should be somewhat below your thermostat rating. You would need access to the shop manual for recommended operating temperature.

 

[rScotty]

The sensor is merely a temperature sensitive resistor that controls the current through the gauge. Generally, they either work or they don't, Why do you think the sensor is bad? What are the symptoms?

That's true about the sensor. The problem is that the sensor may not directly connect to the gauge in today's tractors. Instead, the tend to connect to the engine computer which uses the information in several ways and also sends a signal to a real or simulated gauge on the dash..

For more info on what happens, read what I wrote today about a similar problem.

5205 Running hot

Noticed the 5205 was running way in the red zone on coolant temp. Externally the radiator was clogged with dust and hay particles. Blew it out with compressed air and water. Checked and it was about a gallon low on coolant. Holds 2.5 gallons. Filled it up and it was still running deep in the red...

www.tractorbynet.com

 

[Jerry/MT]

That's true about the sensor. The problem is that the sensor may not directly connect to the gauge in today's tractors. Instead, the tend to connect to the engine computer which uses the information in several ways and also sends a signal to a real or simulated gauge on the dash..

For more info on what happens, read what I wrote today about a similar problem.

5205 Running hot

Noticed the 5205 was running way in the red zone on coolant temp. Externally the radiator was clogged with dust and hay particles. Blew it out with compressed air and water. Checked and it was about a gallon low on coolant. Holds 2.5 gallons. Filled it up and it was still running deep in the red...

www.tractorbynet.com

You make a good point. However, IIRC, the TN70 is not a common rail, electronically controlled engine. I believe it has a hydromechanical injector pump.

 

[rScotty]

You make a good point. However, IIRC, the TN70 is not a common rail, electronically controlled engine. I believe it has a hydromechanical injector pump.

Thanks. Yes, it's a possibility that checks all the right technical boxes. What I don't know is how the injection of your TN70 is configured. I wrote the post I pointed you to in the previous message to for a guy with an overheating JD5205 - which is made about in the years 2000 to 2007. I did so because his just mght have a hybrid system like on my 2008 model 310SG. The hybrid systems were common in the years about 1998 to 2012/14 - depending on HP and emissions Tier level. I don't know if any are being manufactured that way now.

Since yours is in that time period it might be a hybrid too. You might check to see if it has an "engine controller with a multi pin input.

I was sure that our own 2008 was individual mechanically controlled injectors. I mean it's easy to tell, right? Just pop the hood and look. The injectors don't have any wires, they do have high pressure tubes - one per cylinder - and all 4 of those tubes lead right back to the top of what is obviously the high pressure fuel pump. So it's a simple mechanical injection not a common rail and a non-computer type, right??

Well, so what is that black box I see bolted to the frame? Just a connection box? Why is it epoxied shut? I went down to shoot the breeze with the service manager and he says....Uh... it's not that simple.

I may have some details wrong, but the gist is that because in some hybrid systems used during those years it turns out that the fuel flow from the pump to the injectors IS able to be varied by that black box which sure enough is an engine computer - they just do it at the high pressure pump end instead of at the injectors. It's not so accurate and affects all the mechanical injectors the same, but it is a form a computer control, and yes, it does change the delivery fuel curve in response to what the computer sees as coolant temperature, barometric pressure, and a host of other factors.

So at one time it was possible to have an individual injector system, no common rail, and yet still have an a engine computer with the ability to modify fuel flow. BTW, it's programmable - but only by JD. Only they have the program and interface device to sync the engine computer to the ID# of each tractor. That costs extra.

rScotty

mechanics ain't quite what it used to be.

 

[Jerry/MT]

Thanks. Yes, it's a possibility that checks all the right technical boxes. What I don't know is how the injection of your TN70 is configured. I wrote the post I pointed you to in the previous message to for a guy with an overheating JD5205 - which is made about in the years 2000 to 2007. I did so because his just mght have a hybrid system like on my 2008 model 310SG. The hybrid systems were common in the years about 1998 to 2012/14 - depending on HP and emissions Tier level. I don't know if any are being manufactured that way now.

Since yours is in that time period it might be a hybrid too. You might check to see if it has an "engine controller with a multi pin input.

I was sure that our own 2008 was individual mechanically controlled injectors. I mean it's easy to tell, right? Just pop the hood and look. The injectors don't have any wires, they do have high pressure tubes - one per cylinder - and all 4 of those tubes lead right back to the top of what is obviously the high pressure fuel pump. So it's a simple mechanical injection not a common rail and a non-computer type, right??

Well, so what is that black box I see bolted to the frame? Just a connection box? Why is it epoxied shut? I went down to shoot the breeze with the service manager and he says....Uh... it's not that simple.

I may have some details wrong, but the gist is that because in some hybrid systems used during those years it turns out that the fuel flow from the pump to the injectors IS able to be varied by that black box which sure enough is an engine computer - they just do it at the high pressure pump end instead of at the injectors. It's not so accurate and affects all the mechanical injectors the same, but it is a form a computer control, and yes, it does change the delivery fuel curve in response to what the computer sees as coolant temperature, barometric pressure, and a host of other factors.

So at one time it was possible to have an individual injector system, no common rail, and yet still have an a engine computer with the ability to modify fuel flow. BTW, it's programmable - but only by JD. Only they have the program and interface device to sync the engine computer to the ID# of each tractor. That costs extra.

rScotty

mechanics ain't quite what it used to be.

Mine is actually a 2007 TD95D and it's a Tier II engine. The only controllable function on it is an electro-mechanical timing reset on the Bosch IP that is controlled by coolant temperature. When the coolant temperature reaches 120F, the correct timing is restored. The TN series was made before then but I think it uses the same engine Iveco engines so it could have the same system. According to my manual, there is no PCM (power control module, i.e. computer) to control anything and I am so glad that this is the case. If the coolant sensor fails, the engine may run with a couple of degrees of timing "error" and I would suspect fuel usage will increase but it would most likely not effect starting except in really cold ambient conditions. I can't tell you how many offers we had on this tractor when we were selling our Montana ranch, mainly from big California operators who had Tier IV tractors.

 

[rScotty]

Mine is actually a 2007 TD95D and it's a Tier II engine. The only controllable function on it is an electro-mechanical timing reset on the Bosch IP that is controlled by coolant temperature. When the coolant temperature reaches 120F, the correct timing is restored. The TN series was made before then but I think it uses the same engine Iveco engines so it could have the same system. According to my manual, there is no PCM (power control module, i.e. computer) to control anything and I am so glad that this is the case. If the coolant sensor fails, the engine runs with a couple of degrees of timing "error" and I would suspect fuel usage will increase but it would most likely not effect starting except in really cold ambient conditions. I can't tell you how many offers we had on this tractor when we were selling our Montana ranch, mainly from big California operators who had Tier IV tractors.

Yes, that sounds like the same time frame as our JD310SG. I checked, and it is also Tier II. I do not know what the engine computer actually does on this 4045Turbo motor. It might be just timing, but from the hints I heard at the service dept. the computer also has some control over fuel. Unfortunately for us mechanical types, Deere has completely gone away from providing technical information on their tractors. That used to be their strong point.
But they must be doing something right with that approach. Their sales, stock price, and general popularity have never been this high. It's just not good for people who like to buy & maintain older equipment.

Sooo.... do you know enough on your TD95D to talk about the way timing and temperature is related on on the TD95D? I am curious how the timing is mapped to temperature? And if the coolant sensor fails - in what mode does it fail? Unlike old variable resistor type temperature sensors, the JD temperature sensor reports voltage to the controller. So an open sensor or broken wire is zero volts at the controller. The controller then interprets that is overheating..... but I don't now what direction it would change the timng. A JD secret....
rScotty

 

[Jerry/MT]

Yes, that sounds like the same time frame as our JD310SG. I checked, and it is also Tier II. I do not know what the engine computer actually does on this 4045Turbo motor. It might be just timing, but from the hints I heard at the service dept. the computer also has some control over fuel. Unfortunately for us mechanical types, Deere has completely gone away from providing technical information on their tractors. That used to be their strong point.
But they must be doing something right with that approach. Their sales, stock price, and general popularity have never been this high. It's just not good for people who like to buy & maintain older equipment.

Sooo.... do you know enough on your TD95D to talk about the way timing and temperature is related on on the TD95D? I am curious how the timing is mapped to temperature? And if the coolant sensor fails - in what mode does it fail? Unlike old variable resistor type temperature sensors, the JD temperature sensor reports voltage to the controller. So an open sensor or broken wire is zero volts at the controller. The controller then interprets that is overheating..... but I don't now what direction it would change the timng. A JD secret....
rScotty

I don't have access to my service manual. However, I think it is binary; below a coolant temperature of 120°F, the timing is retarded 2°. Above a coolant temperature of 120°F, it is advanced by 2° back to design timing.

It is done internally to the hydromechanical Bosch Injection Pump. (As I said, I don't have access to the service manual. It's in our storage container since we moved to Idaho.) If I were designing the actuator I would have it fail to normal timing. 2° timing change is miniscule since I think this is just a "rule beater" to satisfy the EPA. during Tier II certification. I notice no difference in performance and the exhaust is invisible after startup.